Various reports are coming in stating that Apple's expanded its 14-day exchange policy to cover at least one month, maybe two. That means if you just bought yourself a 3rd generation iPad, you might be able to nip into an Apple store and swap it for a new 4th generation one right now for free.
Basically, it looks like this is operating under Apple's managers' digression, which means you'll have to be nice, but firm about it. But, it's well worth a try for sure. In my experience, if you're nice to the Apple staffers, but stick to your guns, you normally get your way, as Apple wants to keep you sweet.
Let us know if you get any luck in the UK with your exchanges, like some of our American cousins have. [Cnet]