Good news!
eBay did decide in favor of the buyer as I hadn't shipped the iPad 2 with a tracking number (long story short, I didn't realized Priority Mail only comes with tracking when you buy postage online). So, I immediately called eBay, and spoke with a very nice woman there in their claims department. I very politely explained my concerns that:
- the buyer was a scammer
- they hadn't responded to most of my emails
- didn't seem at all interested in recovering the iPad 2
- only seemed interested in the refund
- made suspicious and contradictory statements
- they had purchased over 20 iPad 2's in 3 weeks, yet re-sold none on eBay
- that the iPad 2 I sold them had been registered, proving I had actually shipped it, since I still have the receipt with the serial number on it
I asked her to look at the number of cases the buyer had opened claiming the item had never been received. I also pointed her to this thread to show her that at least one other person has had the exact same problem with this buyer. She mentioned that she agreed with what I was saying, agreed that the buyer had made some really suspicious and questionable decisions, and asked me if I would mind holding for a few minutes while she looked into the case further.
After only 5 minutes of waiting she came back on the line and informed me that eBay had decided to overturn the decision, refund my money back to me, and suspend the buyer's account due to bad behavior. Today I logged on and saw that the buyer is now no longer a registered member of eBay:
http://myworld.ebay.com/yenta888/
So, it all worked out in the end. And next time I'll make sure I take the proper steps to protect myself.