Current Gen Consoles
That's current gen consoles, since consoles take a long time to develop and have a life of, what, 7 years approx before a new one is due?
That means that the PS3 is not due a successor till 2014?
The PS3 was an order more powerful that the PS2 so its probably fair to say that the PS4? will be an order more powerful than the PS3
PC Add in boards are released to the public in small increments, but that's not how the technology advances, it makes a nice big jump. We, the consumers only get small increments so the hardware developers get a nice ROI. eg my ATI 5970 is better than the newer 6x series, but you can be sure that by the time the series has run its life it will have better boards etc.
So what ? Well consoles have to implement hardware and then they are stuck with it for the life of the console, no upgrades, just improvements in software use of the hardware, so its inevitable that other, newer technologies will catch up to a degree.
If we never see another console then I think its true that mobile devices will catch up. But the next console out will kick that back to touch.
The comparison does not take future console plans into account, so IMO, its a bit invalid.
However they could still be dominant for things like on-live, because delivering on-live on a nice fast tablet with decent video playback will work fine, probably just as fine as your PC (albeit without the 30 inch monitor - until wearing goggles is not too geeky) but that's not the same thing as mobiles beating up consoles.