It's really, really not. I don't play it anyways so what's the point in keeping it?
Yeah trophies were brought in a firmware update around April 08 I think. Older games like MGS4 and RFOM don't have them but quite a few games, like Buzz! and Uncherted had them patched in. If a game is in development after Jan 09 then it has to have trophies, so pretty much every new game has them.