As for the man in the first post: Though he is in an irregular marriage, he can return to the church, but not the sacraments until such time as his decree of invalidity goes through. I have several parishioners that want to be in contact with the Church of their childhood, but cannot marry in the Church. They are content to "be at Mass" and live with the consequences of their choices while absent from the Church. What is at stake here is the acceptance of the Church's authority to impose sanctions on irregular marriages. Truly generous persons (on the part of both the Catholic and the previously married Protestant spouse) can accept the authority of the Church, or at least accept that it is important to the Catholic party and choose to go along with him for the sake of their current living situation.
The sanctions of the Church are meant to bring one into conformity with the Faith, and so the withdrawal of sacraments from those in irregular marriages hopes to invite the errant into a regular marriage because of their hunger for the Eucharist

You can also have a marriage "sanitized" after an annulment. This is in the event that one of the spouses does not feel that their current marriage is invalid and does not need to be redone.

Joy-
I believe the Church assumes all first marriages between one man and one woman are valid, until annulled. Marriage between two non-baptized people is deemed valid, but not sacramental, because baptism is the gateway for all other sacraments.
If two Buddhists convert to Catholicism, they would need their marriage blessed by the Church in order for the Church to deem it sacramentally valid.
My qualm is with the criteria for annulments. As Jimmy spelled out in an earlier post, the Vatican has recently set forth new definitions for its criteria to judge marriage validity in annulment proceedings.
Non-sacramental marriages can be easily annulled, because the grace inherent in the sacrament was not present. The new instruction states that a Catholic who has not documented a formal defection from the Church and marries outside the Church has entered into an invalid marriage, and thus the annullment process would be easy under this circumstance.
My argument is that it is unwise to annull such a marriage because two baptized people who enter into a marriage contract (in the Catholic Church, this requires freely making commitments to fidelity, openness to children, and marriage until one partner dies). If the marriage has all of these at any point in the marriage, it becomes valid and breakable only by the death of one spouse.
For the sacrament of Matrimony, the couple is the minister, and the Church is an official witness that blesses the marriage. That is why a deacon is an acceptable minister. But the Church's witness is to put the stamp of approval on the marriage, and marriages between Protestants, Orthodox, or Schismatics such as SSPX (I assume) are also deemed valid and sacramental.

Is the marriage between two Jews considered valid? How about between two Moslems, or Buddhists? What about a civil marriage between atheists? Which kinds of marriages does the Church recognize?

"they were bound by the canon law of the Church"
But so are SSPX, Chinese bishops, laicized priests who says mass, etc. These offenses by clergy are very much against Canon Law, and incur excommunications, but these sacraments are deemed valid.
It just doesn't add up for me. I understand how Canon Law tells you what you should and shouldn't do to remain in communion with the Church, but I don't understand how in some cases it can render one sacrament that uses the valid ministers and matter invalid while in other cases simply illicit.
Maybe I'm unclear on illicit vs. invalid sacraments (I've only really heard the distinctions used for Ordination and the Eucharist), and I can understand how the couple might excommunicate themselves, but to me it seems they would be validly married and thus ineligible for an annulment.

But I don't see how the marriage is invalid, considering the ministers (bride and groom) and the matter (the vows between the two) were proper for the sacrament.
Because, being Catholic, they were bound by the canon law of the Church.

Billy, I guess the issue of whether an annulment is infallible was a rhetorical question... Obviously, an annulment is (for a large part) based upon human judgement. A more liberal diocese may grant them at higher rates than a more conservative one (although I've met only one person who tried and couldn't obtain one).
I guess my criticism has more to do with the canonical guidelines for determining marriage validity. It seems to me that the guidelines in Canon Law really have more to do with licitity than validity.
My layman's stance on the above-mentioned marriage between lapsed Catholics would be that their marriage was valid, however it was illicit in that they did not marry according to the Church's regulations. Perhaps by doing so, the couple incurs automatic excommunication for their actions. But I don't see how the marriage is invalid, considering the ministers (bride and groom) and the matter (the vows between the two) were proper for the sacrament.
I just don't see how it's much different from the illicit bishop's ordination in China. In that case, the Church presumed that the ordination was valid, and thereby the Bishops were deemed excommunicated.
An SSPX mass is considered valid, but illicit. The Vatican and Canon Law do not deny that the bread and wine become the body and blood, soul and divinity of Christ.
All I'm saying is that I fear that a lot of people out there are getting "married" with the Church's blessing, when in fact one of the partners already has valid sacramental unity (in the eyes of God) with another person.
We need all of God's graces we can get. Especially in a marriage in today's age.

Mike, I believe that in a previous response to a question, Jimmy indicated that annulments are not infallible.

Jimmy;
The one thing that is rarely mentioned in answers like yours is the very real possibility that the first marriage was/is valid and that she was/is not able to marry someone else.

Jimmy-
Dunno if this is 100% relevant to the conversation, but I have been thinking about your previous post on attending weddings. Is the Church's recognition of a marriage infallible, or is it merely the Church's best judgement as to whether a sacramental marriage took place?
For example, if a Catholic was once married and then divorced, and a bishop later deems the marriage as annulled, then marries another person in the Church, does that mean that in the eyes of God, there is a 100% guarantee that God recognizes marriage #2?
I was taught (and please correct me if I am mistaken) that in the sacrament of Matrimony, the ministers are one unmarried baptized man and one unmarried baptized woman who pledge a) fidelity, b) a lifelong commitment, and c) Openness to children.
In that light, two lapsed unmarried baptized Catholics who sincerely pledge the same in a Protestant church would seemingly meet the above criteria. Under the new criteria laid out in your previous post, this marriage would be deemed invalid according to Canon Law. If they divorced and one of the two sought and was granted an annulment, would that person's second marriage (in the Church) be a valid, sacramental marriage in the eyes of God?
I am not talking about culpability, obviously if someone sincerely believes that the first marriage was invalid (and the Church agrees), the person is not knowingly committing a sin. Could that person, however, be unknowingly married to another person.

Dear DJ,
My civil "Certificate of Registry of Marriage," which I happen to have a copy of at hand, includes the signatures of:
1) My wife
2) Me; These two were for the "Affadavit" section.
3) County Clerk for the "License to Marry" section.
--> First three are before one has in hand a "License to Marry
4) Witness 1
5) Witness 2
6) Deupty Commissioner of Civil Marriage (Person performing Ceremony)
--> These three are at the time of Civil Marriage
7) Local Registrar to record the County Record
--> Final one is when the document becomes public record
At least in my state, there is no such thing as a Civil marriage without two witnesses.

So what if this person's wife were only married in front of the JP with her first husband? Would she still need to get an annulment?