I'm pretty agnostic, when I'm not busy totally ignoring the supernatural world, if any. As I understand it, the entire Rapture business as people talk about it now is pretty much a creature of 19th Century evangelicals, and was not a part of any mainstream Christian theology before that. The 19th Century also gave us the Millerites, a classic case of Doomsday is X date, then when it doesn't arrive, they scurry around recalcuating and waiting for a new Doomsday.
All seems rather pointless, really. If there is a Rapture, what is there to prepare for? You're either worthy or not, if the idea that it's on a particular date is all that's keeping you from doing stuff that'd send you straight to Hell, I'm betting you aren't gonna make the cut anyway.