I agree with paul, you have to respect the event you're shooting... To almost every bride and their family, this is the single most important day of their lives... There will be a lot of pressure to perform, and capture the moments (no second chances for the kiss, the bouquet toss, etc.).
I shot my first wedding as the prime photographer, luckily for me, it was a small wedding for a friend who didn't intend on having a photographer in the first place. She said no pressure and that she didn't expect much, but it didn't mean there wasn't pressure to perform.
anyways, to answer your question, with the gear you have, you can shoot a wedding. however as mentioned in the previous post, you may want to step up to a 70-200 2.8 or you'll have to bump up your iso to compensate or use flash.
I shot my first wedding with my 40d, 70-200 2.8 IS, 10-22mm and 580EX with a friend as a second shooter using my XT with 28-135 IS and 70-300mm IS no flash. So I think you should do just fine. Just plan your shots out (make a list of must have shots), take a lot of extra batteries and CF cards, shoot raw if possible, it saved my butt several times, and practice practice practice!
have fun too!
5D MKIII|7D w/ Grip|EF-S 10-22MM f/3.5-4.5|EF-S 17-55MM f/2.8 IS|EF 24-105MM f/4L IS|EF 50MM f/1.4|EF 70-200MM f/2.8L IS|85mm f/1.8|35mm f/2 IS|70-300MM f/4-5.6 IS|580EX|Manfrotto 055PROB|2x PCB Einstein 640