Thanks for the explanation, Ish. If there is a precedent for a Queen to have a "Prince Consort," I don't understand why King Charles couldn't have a "Princess Consort." Of course, Victoria was Queen when she and Albert married, but Charles and Camilla will be married when Charles becomes King.
Charles could very well create a title Princess Consort for Camilla if he so wished.
What he cannot do as monarch is strip her of the title Queen Consort - parliament has to do that.
They can go one of three ways:
1. Charles creates a Princess Consort title for Camilla and she would use it instead of the title Queen Consort, while holding both (similar, but different, from her current situation as Princess of Wales/Duchess of Cornwall)
2. Charles creates a Princess Consort title for Camilla and Parliament strips her of her Queen Consort title, essentially creating morganatic marriage in Britain. This becomes trickier when you consider the other realms - does each realm have to introduce such legislature, or is it enough if the UK does so? Personally, I tend to think the former
3. Camilla becomes Queen Consort. The media makes a fuss about it, some people are disappointed or angered, but in general people move on
Personally, I think the best situation is #3. The first two both establish tricky precedents that can effectively end 1000 years of tradition. If Camilla isn't allowed to be Queen then what's it say for future consorts? Furthermore, in not allowing her to be Queen we're creating morganatic marriage - at a time when many other European monarchies are ending morganatic marriages.
Comparing Camilla's situation to that of the DoE or Prince Albert (or other male consorts) is a bit unfair. Women have always taken the titles of their spouses in Britain, men have essentially never done the same. Britain has had 5 undisputed female monarchs, 2 of whom were married to "kings" and who lost a lot of their power and position as such, and the other 3 who were married to "princes" and were able to maintain their positions. The idea of a King consort brings up a whole other set of issues associated with a woman's position in a marriage.