holy thread revival batman ... given that oct 21 is now in the past the really pertinent question is how did it go ?
That aside i'm with phil on the iso question- I shot weddings for years with a 20D and a 40D , and then a 40d and a 50D, and then a 50D and a 6D without problems and none of them bar the last is any better on iso than the 7D ... thing is photographers worry about noise etc so thats the feedback you get back from photographer - 99% of the time the client could care less so long as its reasonably sharp, she looks great, and you capture the mood and the moment.
A couple of years back I did a wedding while I was somewhat ill with Man Flu (cancellation was not an option) I managed to leave one of the bodies on iso 1600 for the whole day , and to burn out spots on the dress in some of the bridal shots - tbh I hated the whole set. I presented the CD with more than a little trepidation ... however the bride absolutely loved them and wound up ordering an A1 canvas of what i would have considered on of the worst shots for both noise and burn out.