For me, absolutely. I have a Wii and PS3 - both for their exclusives. Mario, Zelda, etc. on the Wii, SOCOM, F1, MLB: The Show on the PS3 (just to name a few).
As a media machine, I barely use my PS3, which is probably a shame. But I don't have any Blu-Ray movies (yet), and I don't need to store my music and such on there (though again, I may next summer, if I can stream to my wireless outdoor speakers with a media program).
Ultimately, I don't think the price is justified, but it is a very powerful system. It touts reliability which the 360 simply does not have, and offers an increasingly impressive lineup of both exclusive and cross-platform games. From what I've heard, most developers will be switching to the PS3 to build their games from starting in 2008, ending many of the problems we've seen with 360 --> PS3 ports. Similarly, the improved developers kits released by Sony have overcome most of the "issues" people bitched about when the system was in its early stages.
Basically, if you want, I'd wait until the holidays to pick one up. There is a huge rumor of a price-slashed 40 GB version heading to stores for this Christmas, and you might want to get that one.
I snatched one up when they dropped the price on the 60 GB SKU, and Circuit City had a deal already in place for a free controller and some other good shit (so I got lucky).
I love my PS3 - and as more games come out, and I use some of its other features (video playback, music, file storage) more often, I think it will ultimately justify the investment.
Anyways, my advice to you is to look at the list of PS3 games on Wikipedia (thanks to XDCX), and compare it to the 360 list (if that's your debate). Weigh the reliability concerns of both consoles, the exclusives, and what you want out of your machine (360/online play for a fee vs. PS3/less online features, but free), and make your decision thusly.
I'm happily PSWii!