Well the media found out that a Resistance 3 billboard was made and filmed recently for a movie coming out in 2011.
So Sony is planning to stay competitive until 2011, which shows that this gen is probably going to be the longest gen of gaming consoles in history.
Project Natal is also treated like Microsoft as a whole new console release next year in 2010. So Microsoft is probably not even thinking about the next gen right now.
Natal and the lame PS3 wand is going to be a "sub-gen" of gaming. Plus Crytek even said that graphics technology would probably remain the same until 2013, which I think is pretty true. Looking at the advancement from the humble HD beginnings of Call of Duty 2 to the graphical splendor of Uncharted 2 and Modern Warfare 2, it looks like devs can still squeeze more from this gen's capable and versatile hardware. Even my Nvidia 8800 GT can still run the newest games smoothly on optimal settings. The 360's triple core Xenon Processor and powerful graphics card and the PS3's amazing cell processor can surely have more potential than my old trusty.
It's good I chose to enter this gen. It's got the most bang for the hefty buck.