yea i say get it replaced. i just got mine replaced today. the genius guy was really cool. mine was replaced when there was the recall and my replacement would only retain 50% health with 65 cycles. he told it was out of warranty but he'll replace it anyways since this battery was the replacement for the recalled battery. my new battery now has 99% health with only 1 cycle. awesome! haha. and he also told me there's a 90 day warranty on that battery if it happens to crap out. i have to say that the oak brook center apple store is awesome. very cool people there. the week b4 i went in and ask about the bad magsafe connector that was coming loose. one guy just looked at it and was like here's a new one, didnt even asked any questions. now's tha's wat i call service.
I believe the "official" unwritten rule is that any battery with an age of about a year or less, but most importantly with less than 300 cycles, and has less than 80% capacity, can be replaced by a genius pretty easily.
I just had my wife's MBP battery get replaced under warranty. After 11 months, 118 cycles, it had 63% capacity. Got a no-hassle replacement at the Genius Bar.
On my MBP, I have 90% after 12 months with 186 cycles.