This isn't about PC versus consoles. It's the phones and tablets that are changing things the most right now. There's been a boom in casual gaming... Angry Birds, Fruit Ninja, etc. It's the same market Nintendo went after (or, at least ended up finding) with the Wii.
It's not gonna kill the consoles though, or PC gaming. The games you can play on a phone or a tablet are simple. Time fillers, for when you on a bus, subway... waiting at the airport... whatever.
There will always be people who want a more complex deep game with a big screen / monitor and a controller / keyboard and mouse.