Personally, I think the OP was wrong when he said that the PS4 will launch 7 years after PS2, but what do I know...
I would say we will see:
PS4 in 2012 for $350, large HDD, many games downloadable, well integrated online service before launch, I would expect the PSP 2 to arrive 2 years earlier ready to be connected. They will have FF XIV, GTA VI, Resistance 4, Jak 5 and a few new IPs for launch
Xbox 3: 2011 for $400, similar to PS4, but less stuff generally
Wii 2: 2010 for $300. Still with motion controls, but with a wireless nunchuck and better Wii mote. Far more peripherals, will have a 1:1 lightsaber game. Will have a large HDD for massive collection of remade VC games, with HD graphics and controls adapted for the wiimote