The singleplayer portion alone is at the very least six hours long. Coop is said to be of similar or equal length, and where you play as robot characters (featured on the cover art). The latter also is structured in a way that allows for additional content to be thrown in the future. And knowing Valve, that future content is likely to have no price tag on it.
Seriously now lads, does anyone know what this game is comprised of content-wise ? I mean - and don't get me wrong - Portal 1 was fine as a Steam standalone game and as a part of fantastic package (Orange box) but i can't see myself spending 50-60 euros for a boxed product if the game proves to be 3-4 hours long you know ?
I've heard that the co-op is different that the SP portion, any truth to that ?
Any mention of how long the game will be from Valve's part and what game-modes are in it ?