1) There were several copycat shirts that came out on Cafepress/Zazzle shortly after mine started gaining traction. The shirt concept itself is not completely unique as we've all seen "I SURVIVED ..." shirts before, but the copycat shirts used the same font, word placement, and everything. Am I upset? Absolutely not. Those just validate my idea. And I wasn't too worried about losing sales as the copycats were way overpriced ($24+s/h vs $16) with lower quality and far inferior presentation. I would be surprised if they sold any at all, really.
2) The copycat shirts went as far as using very similar descriptions for the shirts. Not only does this show a complete lack of creativity, it shows that I may have been onto something with the humorous/witty/questionable description that has been mentioned here a few times. Is it offensive? Possibly. But I think it did more good than harm (in terms of measurable things like sales and hits).
Just thought I'd throw those thoughts out there for pondering.