Time for next-gen...?

Do you think it's already time for the Xbox 360 and PlayStation 3 to leave the shelves and make place for the brand-new Xbox 3 and PlayStation 4, or do you think that they're both able to keep up for another couple of years? Microsoft's and Sony's 10 year lifecycle seems too long to withstand the pressure of gamers wanting something new, and all the life and power has already been sucked out of the systems by developers. Games are getting bigger and bigger, and Xbox 360's disc-swapping solution is getting annoying. Kinect and Move haven't really succeeded to 'upgrade' the systems for another 4-5 years.  I personally think it's time for Sony and Microsoft to introduce their next big systems. What do you think?