I don't think any of the current consoles will be doing particularly well after another 2 years. I don't see the PS3 Wiimote or the Xbox Kinect really extending the life of the systems, but rather just giving them a 2-3 month boost which will settle back down to where the system would otherwise be anyway. They're just add-ons; not new controllers that are compatible with everything.
Though if Nintendo gets their next machine out significantly before the PS4 and Xbox 4*, it isn't likely that Sony or Microsoft will do very well in the next generation. Nintendo already proved they are able to take the distant lead, and they're also proving they can gather heavy support with the new 3DS.
*I realize it is only the third Xbox, but Microsoft won't want to seem as though it is behind the PS4 numerically.
I describe myself as a little dose of toxic masculinity.
