I have a question about the wedding. It was my understanding when Charles married Camilla that they could not get married in Westminster Abbey because commoners could not get married there. But isn't Kate a commoner? All the buzz seems to indicate the Westminster will be the venue.
I'm not super keyed in to this type of news most of the time, but I thought that Charles and Camilla got married outside of the Church of England both because Camilla was a divorcee (whose spouse was still living), and because Charles and Camilla had carried on some sort of relationship
while they were married to other people. They had to go and apologize for their adultery before any priest would bless their union, I think.
I'm hardly an expert, but as far as I'm aware there is nothing about British traditions or law that specifically forbid a commoner from marrying royalty in Westminster Abbey or from eventually becoming queen. Things like divorce, however, can, since the monarch is supposed to be the head of the Church of England. If I'm remembering my British history correctly, Queen Elizabeth's uncle abdicated the throne so he could marry a divorced American woman, making Elizabeth's father (the second son) king, and putting Elizabeth directly in the line of succession.
I was curious, and poking around on Wikipedia, and apparently there is a concept called "morganatic marriage" that exists, but not really in the UK. The idea is that when people of unequal rank marry, the higher-ranked person's title is not granted to the spouse or to the children of that marriage (though they are otherwise legitimate). It was most common when high-ranked men married lower-ranked women, since women rarely had hereditary titles they could hold in their own right.
But if Wikipedia is correct, there is actually no tradition of morganatic marriage in the UK. Apparently, the fact that Camilla is not now styled as "Princess of Wales" is mostly in deference to public sentiments about Princess Diana, because it is legally a title she can claim. Ditto her eventual title when Charles assumes the throne. And in fact, when King Edward (Elizabeth's uncle) wanted to marry his divorcee, one option that was considered and then rejected was morganatic marriage (it was decided that he could not be king and marry her -- he'd have to pick one or the other).
It's an interesting few paragraphs, in any case: http://en.wikipedia.org/wiki/Morganatic_marriage#United_Kingdom