I had a similar experience at the Apple Store in Towson, MD yesterday. I have an early 2011 15" MacBook Pro (2 GHz Intel Core i7 with 8GB RAM). I made this appointment after opening up my laptop a week ago and noticing that the trackpad was bulging out of the aluminum frame. Having read through this thread and having a background in computer repair, I removed the battery as I was concerned that it might potentially cause collateral damage under the hood. After I removed it, I scheduled an appointment at the Genius Bar. This appointment was one of the worst retail experiences I've ever encountered, and I'm one with a high tolerance for frustration.
After a Genius Bar employee checked me in, I waited and waited wondering how this would unfold, and I wasn't expecting to be treated to a free replacement. As expected, I was informed that I too would have to foot ~$130 for a new battery, but that isn't what made for a truly awful experience. The employee proceeded to tell me that the swollen battery was normal for a battery at the end of the life cycle and that this happens all the time. He then proceeded to scold me for removing the battery on my own volition. I stated that I had the proper tools to remove the battery and proper training. Rather than understand my frustrations, he continued to quiz me on whether I properly grounded myself before removing the battery. After I described that I did indeed ground myself before doing so, he went on to state that no one can simply just open up their computer and remove a part. His own analogy was "I can't work on my Volkswagen and then expect the dealership to honor the warranty." At this point, he was visably defensive, rude, and spoke to me like I was a child. He never asked when I purchased the battery but only focused on the fact that my warranty expired.
When I proceeded to ask how this was "normal," he restated that this happens to all MacBooks. I then inquired: "So, every MacBook will experience this problem?" With confidence, he stated "Yes."
I felt that if I continued the conversation, I would say something that I'd later regret, and it's not his fault that the battery swelled on me. I put this battery to work over the course of seven years in a Ph.D. program.
I inhibited my frustration but left the battery at the store so it could be recycled.
