Well as it currently stands, and has been, and will still be for a good many years, your typical FPS (Doom 17, 18 or whatever they are going to make next), your typical RTS (Command and Conquer when the Russians finally win) and your typical 3rd Person action game (Raiding the Tomb of the Tomb Raider) will continue to be the most sold and oversaturated genres out there.
Well at least we can count on the odd snowball in hell type of people out there like these guys ...
http://www.darwinia.co.uk/