Tina, when I bought my 04 gto this summer I researched a ton on the cars and tried to find the most pros/cons about them. I was really nervous since the gto I bought was relatively modded (cam,boltons,etc.). A stock gto seems to last pretty well. Its only when you start playing the modding game that things start getting sketchy. The main concern I found on these cars are rear end/ differential/axles. The diferentials in these cars aren't very stout at all esp when you start putting some power down. This also applies to the axles. I have the 6spd version w/ the ls1 vs. your ls2 with auto but this still applies. One site I found to be a great help is http://www.ls1gto.com this site also is dedicated to LS2 gto's as well. after all the rearend/ dif/axle talk mostly everything else on the car is similar to fbody's in terms of engine/tranny concerns, etc...
EDIT: forgot to talk about wheelhop. I myself haven't had any issues with wheelhop. BUT the car has the Peddlers rear suspension kit installed on it so that may be the reason. Either way its a hit or miss. I hear ppl talk about wheel hop all day then you got ppl like me or Kirkso5o talk about never having wheelhop when he owned his GTO.