Since we are talking about games in general i'll play Devil's Advocate for a while.
A year ago i would have been like most of the Codex, telling this guy to go get himself fucked up his ass and all that. Now i am with him at least so far as we say SOME games do not need to be long, regardless of quality. A pure RPG? Yeah, sure. Make it so long it hurts, since the investment in character development and exploration feels pointless if the game ends too soon. But, on the other side - action games, or games with an emphasis on action over other elements? The shorter the better, regardless of quality.
Take "Bullet Curtain" shooters as an example. You can finish them in one, thirty minute long, sitting. The point is that you have to be pretty good at the game to survive beyond the first five minutes in anything beyond the easiest setting, and a GOD to do it in the harder ones. You can spend half a year or more to 1cc the fuckers "cleanly", without exploits or "tricks", on the oh-so-fucking-insane hardest setting - And some even then can't do it. You MUST spend even more to do so consistently and without too much of a hassle, if you ever even reach such skill level.
Another example would be the Freespace games. How long are they? I usually cleared them in two nights, back when i was doing the "middle" setting (and without dying once but in the "lucifer" mission, i'm that cool), so not a lot of lenght right there. Now go an raise the setting to the hardest - What, you just took off and are already exploding like a moron? Cool. Now go finish the game like that. I'm seeing weeks, if not months (in case you are a little fresh on the "space sim" thing) of "game value" right ahead.
Both examples seems to me far more "money worthy" than any game you do one, two, or three runs and forget about it - regardless of how long those runs are. So the point isn't really how long the game is, but how much time and enjoyment you can take from it.
I would hope games become shorter, actually. Most games, regardless of genre, have most of the content be little more than filler - More battles to grind through, some uninteresting sidequests disconected from whatever objective you have, etc. WTF? I am not against turning games into a series of unique "set pieces" that runs through, what? Six, eight hours? I'll be going back to re-experience those unique, cool moments often instead of a game that had some insteresting moments separated by hours of the same shit over and over and over. And i am not the only one.
Better yet if those eight hours of unique set pieces are hard as fucking hell and you need some real skill and months of practice to survive anything beyond the first scene. The problem, then, would be games becoming easy (not simple, but easy - simple CAN be cool, if it is simple because the test is upon real skill instead of "gameisms") - Not the games becoming short.
Just my two cents about the general topic of games becoming shorter.
