I don't know if the 2000 version is the same, but who in their right mind decided to put the serial number/bar code right at the bottom side of the Vita?
I've owned two and the same thing happened, without me realizing after the fact. On my first model, the serial number sticker came off. It's important when taking it in for repairs (I think they will deny the system) and Gamestop can't take it in without it.
On my current model, the serial number completely vanished. So it's made out of a cheap sticker/ink. If you are using the Vita to browse, it's most likely where your thumbs rest, causing them to fall of in time. Such an oversight.
Searched on other forums, and got some results of people losing their serial numbers too.
Did they fix this for the second model? Has this happened to you before?