From a point-of-sale perspective, a clerk is able to hand one box to a customer for a PS3 purchase while that same clerk would have to hand over multiple boxes to a customer looking to match the experience they can get with a PS3 and charge them a lot more in the process: 1) Xbox 360 2) Xbox Live Subscription 3) Wireless Adapter 4) Blu-ray Player.
As far as games are concerned, last I checked, COD:MW2 is going to be on PS3 this Fall, Madden is on PS3 already, Assassin's Creed 2 is on PS3, and Gran Turismo 5 will be on PS3 (possibly before Christmas) in addition to many other games including the other Sony exclusives. To say the X360's lineup outside of Halo, Fable, and Gears of War is superior to the PS3's is debatable and laughable in my opinion.
In addition, the Panasonic Blu-ray player that matches the PS3's quality in playback currently retails for $299.99 at most retailers ($219.99 at Costco). From that perspective alone, a consumer sees the PS3 much like consumers saw a PS2 with DVD playback - a great deal.