You better get used to calling her Katherine. Once they are married she will no longer be Kate. I saw a special (well, didn't really SEE it but listened to it as I did things around the house) about them.
I think the reason people over there are so laid back about it is because its not THAT big of a deal to them. It's sorta like Chelsea Clinton getting married. Eh, who cares? Of course it will be beautiful and extravagant. But I won't be watching.
Oh, and for the record.....I could care less about Charlie Sheen (I'm so sick of hearing about him), Lady Gaga (can't stand her!!) and Snookie (never watch that show).