I had an issue with the mic on my iPad 2. Admittedly I never really put it to use, but I was able to test it with video recording and Skype when it was brand new.
A week ago I tried to face time with someone and they reported that all they heard from my end was static. I tried recording videos with the same results.
I took it to my nearest Apple Store, they agreed to replace it right away. They informed me it would take roughly 10 days (that was their average I guess) for a replacement. The next day they called and told me to pick my replacement up.
The replacement appears to be a refurb; it didn't come in a brand new box, rather just a plain brown one that was well padded.
To my surprise (and satisfaction) this one has Zero backlight bleed issues. My original got pretty horrific.