Yes the DS lite is really sweet. I am still waiting for mine.. it will take a while though, they really did sold out.
Yes, I loved Phoenix. I believe it is nota game for everyone... But I recommend this
trailer. Just keep in mind that the trailer is "tongue in cheek" humor, the game cases are about murders. That doesn't mean it doesn't have humour all around. The game is just like the trailer, but without voices (I believe it would not fit in the DS cart, nor a UMD if it did). I believe Snatcher fans should give it a try, though the setting and differences might not be attractive to everyone.
About good DS titles I have the following that I highly recommend: Mario Kart DS, Sonic DS, Viewtiful Joe, Castlevania and Meteos. I also would recomend the following if you are not "scared" by "childish" and "rare" games: Kirby, Feel the Magic, Rub Rabbits, WarioWare touched and ElectroPlankton (not a game, but a very interesting piece of interactive musical software). Also, if you like shooters, Nanostray is a very good game.