you get so much with a standard Ps3, from wireless networking to Linux. There is just soo much inside it that is still yet un-tapped. And it's fully capable at handling native 1080p resolutions and playing blu-ray etc the list goes on. I think of the Ps3 as futureproof. Where's the 360 is going to be outdated soon with it's inferior dvd format and the xbox arcade having no hard-drive complicates the future for big games and console updates. No wifi. The Wii I would expect to be the least future proof having no HD capabilities in any way, but it has proven me wrong again and again so there's no telling with that one.
I still say the Ps3 will last the longest, maybe not ever sell more than the Wii. But it is built for the future of gaming.