(admittedly spinning a bit off the Wii discussion here, but hey, it's off topic)

Both the PS3 and 360 have a good assortment of games available through their online stores. While Nintendo went the route of only offering older games through their store, The PS3 and 360 are packed with an assortment of new games for pretty cheep. The recent one I downloaded on the PS3 is Pain, an odd physics based destruction game, where you use an invulnerable human fired from a slingshot. Even fill production games are downloadable like Warhawk.

As far as released in store games on the PS3 side, you named 2 of the exclusives, and other releases I can think off recently were Folklore and Heavenly Sword. Many games are being released on both the 360 and PS3 now, like Rock Band, Guitar Hero III, Call of Duty 4, The Orange Box and so on. So in the end, if you do come down to only a PS3 or 360, pick the one that has the exclusives you want, as enough other games will come out for both.

For me, I just forgo the whole one is better then the other, and ended up with all 3 under my TV. Even 3 consoles every 5-7 years is cheeper then what it takes to keep a gaming PC up to date. Though the fanboy in me does root for Nintendo, just for proving to both Sony and Microsoft that spouting tech numbers two years in a row at E3 did them little good.