I just bought my PS3, so I may be a little up on it right now. Let's break the systems down into what they can be used for:
1.) Games. With exclusivity on the way out, this is kind've a moot point. The real question is going to be answered by the processors. The PS3, in theory, can handle more information than the XBOX 360 by a little bit. XBOX's library at this time is considerably higher than the PS3, however. The online store for PS3 is something to remember - I just bought FFVII for $10.00 and its sittin on my harddrive ready to be enjoyed again and again. I'll go deeper into that in the online store section.
2.) Media outlet. I will say that PS3 is superior in the media department without any questions asked. I can stream my anime to my 40" LCD through PS3 media server in beautiful 1080P with the ability to fast forward and rewind - something XBOX can't do with the same software at least. The load time is also considerably shorter for the PS3, almost instant where XBOX took about a minute to "load" the show. If you throw in the Bluray as well (for a real HD junkie) you're talking about multimedia domination. Though these are things I could do without, it's those nice perks that make it worthwhile.
3.) Online play. For the price - PS3 (free). For the win - XBOX360. While $8 a month (or $50 for a year) microsoft is doing it right. I haven't really played anything online for the PS3 but I've seen the notification that I've been randomly disconnected from the network a couple times - that would piss me off if I were in a game. XBOX has a nice way of getting the online gaming done. All of this is based off being directly connected - not wireless. I can't speak for the $100 wireless adapter for xbox whereas the PS3 has one built in. However, if you do use a credit card to set up your Gold Live account be forwarned that you WILL HAVE TO CALL THEM to cancel it. There's no nice button to click to undo your decision which is a pain in the ass of being put on hold and offered several things to make your change your mind.
4.) Online store. I find Sony's to be a little nicer - probably because they have games up that I loved as a child. Almost all of the Final Fantasy games and Grandia just to name a few. I also like the ability to pay a cash amount instead of the gay microsoft points. It makes budgeting a little easier.
Something stupid that no one has seemed to mention is the sound they put out. Not the game sound files - I mean processing sound. My XBOX sounds like a machine gun at times when it's loading things off the disc whereas my PS3 is eternally silent. It's a little irritating when playing something with a beautiful sound track to hear the XBOX go raaataatttaaaghaaaa awtfaaraaa. However minor, it's still annoying.
So I'd lean slightly toward the PS3 for many of the things I've mentioned above. With the new price tag of $300 I don't feel you can really go terribly wrong with it.
