I'm not sure where you are in the world so can't say for sure what the wording will be in your countries consumer rights law but, I don't think any shop would have an issue with you returning that based on the item "Not Being of Satisfactory Quality".
Just take it back to where you got it from and ask for a new one
I think i've seen a couple of people on this forum with the same 'bubble' issue, but no, i don't think its common (yet). Well at least not as common as the cracking issues on the non-unibody mabooks...
but that should definitely be fixed/replaced under apple care- so take it to the genius bar or a apple reseller.
Man that's crazy! I have seen a couple of these on the forums, but I sure as hell hope it's not a common issue haha. Glad you got it fixed though, and good luck with your diagnostic!