Same here. From what I've read it is alot of 64 bit users. Alittle heads up, all I do is plug my iPad in, then when it starts to say Backing Up iPad, I hit the little X in the top center dialog box at the top of iTunes. Then it will proceed to sync my newly acquired apps.
I figure I will let it do a back up at least once a month and just let it go over night or something. Till then, this is an easy fix.