Sounds like it's time to try it on another computer and/or hit the re-order button.
I'd also look for a thread with a title along the lines of "10 ways to kill your arduino" to make sure that none of the conditions than generally ensure destruction could have happened.
You can buy a Meeduino Uno for about $12 or $13 on dx.com, so while frustrating - it's not (hopefully) a really big deal. I've got the Mega from these guys. It seems just fine. (Mega was about $5 more - cheap considering the extra functionality that may be had with the larger ram and flash - not to mention the extra IO ports)http://dx.com/p/meeeno-mn-mb-unomn-development-board-w-pl2303-serial-orange-black-202588