If the next consoles come out in 2013 (sorry, wii doesn't count in this race) then in 2019 they will only be 5 years old, and will not be replaced (sadly) for another 3 years. nVidia may have the parts to get the job done, but that does not mean anyone will be using them.
On a related note, we are already hearing about how the next gen consoles will have 3 year old (4 year old by the time of release) parts in them. This could be the first console release where even mainstream game rigs will be able to beat consoles on quality right out of the box. With the PS2/xBox consoles were a little ahead, then PS3/x360 it was the same quality as a main stream game PC for a few months. I remember being excited to buy a PS3 until I purchased my 9800GT for $180. Then I was really disappointed in the graphics of the consoles and never did end up buying one (besides, I would have to buy a TV to go with it... I think I'll stick with my nice 28" monitor).
But the point is, if you have to have a PC anyways to do work/internet, then why buy a console when you could put the money into a GPU and controller and enjoy better quality games, while getting a better experience for what work you do on it? At least before you could get better/equal performance to a PC, but I doubt that with the next gen.