I don't expect new consoles for a while still, much like THQ. Both Xbox 360 and PS3 are going to have record years for software this year - and there's no sign of a decline thus far. While we are used to a console lifecycle naturally having software sales fall after a 'peak' I think this is more simply due to major software jumping ship to the next console.
What I'm saying is, would the PS2 software sales have declined in the fashion they did, if the 360 / PS3 / Wii wasn't announced and FFXIII, MGS4, GTAIV etc were on it? Is this software decline people look for simply a consequence of software moving to the next platform anyway. Bit of a chicken and egg situation and I think the publishers will be taking a different approach to solving that problem this gen - by sticking with the consoles we have now and not pushing for a next gen for the reasons THQ listed.
I don't think it's even a matter of Kinect or Move extending the life cycle, software sales will always be high if the software line ups are as strong every year as last year, or this year.
I just don't think Microsoft or Sony have any benefit in a new console either - what could they possibly add that the current systems can't do? Graphics are at a threshold now for all intents and purposes, and we've seen they're not a huge selling feature with the Wii anyway.
It's hard to write about Nintendo as I've really no idea what they'll do. I can't see them simply making a PS3/360 style HD console with the Wii brand so... who knows, and even if they did, I don't think it'd lead to any sort of a kneejerk reaction from Sony or Microsoft anyway.