Sorry it took so long to get back to you, but yeah, the PS3 is worth it. Both the 360 and PS3 have the same library, minus a few exclusives, so what was the only real concern with the system no longer exists. The only question I would ask you is which system your friends are playing on, if online is important. That's just about the only thing you have to worry about. As for what games to get, look into Ratchet and Clank Future, Uncharted, if you're looking for a Tomb Raider type game, obviously Metal Gear Solid 4, which raised the bar of what a video game should be, and SoulCalibur 4, which is supposed to be the best one yet. (I wasn't a huge fan of the previous two, but with online now, and the reviews, I'm really tempted to pick it up.) And for this fall, LittleBigPlanet, which is supposed to be addicting as heck, Resistance 2, if you need a shooter fix, and Valkyria Chronicles is supposed to be a very high quality SRPG coming this November. On top of that, you may know that the PSN is known for getting full games, and even the ones that aren't are extremely unique and artistic. PixelJunk Eden is really good (as is Monsters,) Flower is supposed to be excellent, Super Stardust HD is the Geometry Wars of the PS3, Everyday Shooter is right up there with Eden, and Ratchet and Clank Future: Quest for Booty is hitting the PSN in August.
If you have an HDTV, then of course the Blu-ray player is a beautiful addition, if put to good use in the growing age of digital downloads and on demand video. The PS3 is a great media player, however, and will stream, upscale, etc. all the files from your computer. Plus, if you're looking forward to Final Fantasy XIII, the demo is on the Blu-ray release of Advent Children Complete, which will sure as hell make me buy it.
Regarding backward compatibility, current 80GBs are the only ones that support PS2 titles (while all support PSone titles.) In late August(?,) I believe, Sony is getting rid of the backward compatible 80GB SKU, instead, just upgrading the 40GB with an 80GB hard drive. So if backward compatibility is important to you, go out and get a system now, because it's not going to be around much longer.