I find the wedding interesting for a couple of reasons.
1) Its extravagance. How many times do you expect to see a wedding or event like that?
2) The location, history, significance and cultural story. I love English history, so seeing the location (really magnificent) and the costumes and traditions is also very interesting.
3) It is a significant historical event featuring people who have strong political connections with my country.
Madhuri, I agree. I find a lot of things very interesting, and will even support them monetarily, without necessarily agreeing with whatever their "message" is. For instance, in a few weeks, we're going to Europe and we will be paying money to tour Crazy King Ludwig's Neuschwanstein castle, and Hitler's Eagle's Nest. We'll also tour Dachau, though the message against the Third Reich is pretty obvious there.
I've visited Buddhist shrines, and Japanese temples and I don't support either religion. I've also visited "Iron Curtain" countries though I didn't support Communism. And I wasn't on any sort of "mission trip," either!
I love history - especially British, Russian, and German history. Some of that stuff is pretty awful. But it's still fascinating. The royal wedding is history in the making.