You guys are comparing such different genres in your argument over if games are becoming shorter or longer. What's the point in comparing a 6 hour Mario game and a 60 hour Gold Box game? One was made for kids, the other one for computer geeks without lives.
There were lots of short games when I was a kid, I mean the Commodore 64 only had 64 KB RAM. If it didn't load extra levels, games were bound to be short. But the only games that still stick in my mind from those days are the Pool of Radiance's, Wasteland's and Ultima's. Those were all loooong games. Much longer than anything I have played in recent years, that's for sure. Most games nowadays last me ~30 hours, and that's if they are considered long. Jade Empire was beaten in 13 hours (or 14, not sure), by a complete newbie on 'RPG's', his 6 year old niece and me. No challenge, no mind-numbing puzzles, no problems whatsoever.
I mentioned Bard's Tale 3 in another thread the other day, and that got me thinking back to the days of mapping games on paper and spending days, if not weeks on a single problem. I'm not saying that it was better (I love auto-mapping for instance), but I do miss games that require me to think, instead of just having to choose the correct corridor down the forest. Something has changed, play length or something else, because I never see games like Ultima (with its gigantic world filled with towns and caves), Wasteland (with its brain teasing puzzles and riddles) or Pool of Radiance (with its multitude of zones, monsters and puzzles) anymore. I want to be able to get lost in my games, damnit!