First I'll declare that I currently own an Original Wii, an XBox 360, a PSP and a PS3.
The Wii hasn't been turned on for months and was mostly used for Zelda games.
The Xbox360 also hasn't been turned on recently and that's mainly used for platform exclusives.
I can't remember the last time the PSP was turned on, that's really been superseded by smartphones and tablets.
The PS3 (original fat model with hardware PS2 compatibility) is my main gaming machine (primarily because I "know" more people on PSN than XBox live) and is currently getting used for GTAV. It also gets used as the BluRay player so since I've had a 3-D TV for about 9 months I was rather startled the hear the PS4 doesn't support 3D BluRays. I never really used the PS3 for media as Sony never provided .MKV support.
Currently neither the XBox One or the PS4 have me thinking "I want one". If the PS4 was backwards compatible I *probably* would have gone for it after Christmas, just to have the new shiny. But with a backlog of games and several new ones due that I fancy playing I'm happy with the PS3. And I don't want to run a PS3 and 4 - there are enough wires and plugboards round the back of the tell as it is.
So.... until the next Uncharted gets released as a PS4 exclusive I'll probably be sitting on my hands; I can't see the sales being massive.