If all you want to do is play games, then look to the console that has the games you want to play on it. Keep in mind that most games are written to the lowest common denominator, hence most on PS3 will eventually just be prettier ports of existing X360 games, at least for now. Point in fact, Oblivion, it's actually no better on the PS3 than it was on the X360.
Also keep in mind that the term "format exclusive" with respect to next generation games is a misnomer - as they will only stay "exclusive" until the port is done. No one can afford to hold a game title back from potential sales anymore.
That said, on the subject of such "exclusives" the next big one will be the next Grand Theft Auto, which will come out first on X360 - that will make a dent into PS3 sales, but only until the port can be rushed out, probably in time for this Christmas.
Someone mentioned Forza - I admit that I don't like the game at all, but then again I've seen various versions on GT5 and I think once you see the new physics and simulation modeling, you'll be more than a little surprised at what the PS3 is capable of in that respect.
If you want it for more than games, say media centre, downloaded content and next gen disc playback, the PS3 is superior in every single respect.
HD Disc format: How many HD-DVD discs have you seen for sale, as opposed to BluRay titles, at your local JB Hifi (or such) store in Australia?
Hardware flexibility: The PS3 will accept just about every major form of memory stick out there. It also allows you to install any hard drive you like.
Downloading: Xbox live is cute. The Sony store will be selling you more than just games and demos, they will soon stream music and movies - which Xbox Live has no charter for in the foreseeable future... Not to mention that they've limited the majority of their user base to custom 20Gb drives.
Reliability: The X360 has some serious design flaws, and I am not talking about the overheating PCB warping responsible for the "rings of death", but about an issue that is in the process of becoming a scandalous lawsuit of monumental proportions in the coming months... but that's all I can really say about it right now.
Strangest thing, I like the X360 a lot, it's actually very good at what it was designed to do, and that's play games. I also prefer their controller, but now that Immersion and SCEI are friends again, you will see the new controllers before this Christmas (rumble and all).