They won't become obsolete anytime soon. Reduced sales? Yes, but consoles won't dissapear, not even after the inevitable gaming market crash. Mobile and tablet sales will stop somewhere in the future, not everyone on the planet can have a smartphone or buy one new every one or two years, plus the gaming on those systems will go away just as the casuals migrate from device to device. I can see handhelds multiplying their lifespams to counter the growing cost of developing games for them.
You know it deserves the GOTY.