Interesting article from Ars Technica:

"When will gamers finally have way too much of not enough? The tension between game prices and the length of the experience is only becoming more apparent as big-budget, long-hyped releases can be finished in the span of an afternoon. Most recently, Medal of Honor, Vanquish, and Star Wars: The Force Unleashed 2 were chastised by critics and consumers alike for being incredibly brief—all take about five hours to complete.

Games are getting shorter, but not many in the industry readily want to admit it. Setting up interviews for this article proved a Sisyphean task: no one wanted to say their games were too short, and those who created longer games were loath to criticize their peers."