In a recent Uncharted 3 speed run, similar to the one Bethesda just had for Skyrim, a Naughty Dog QA tester played Uncharted 3: Drake's Deception on easy mode to complete the game as fast as he could. His fasted clocked in at exactly three hours, eight minutes.
Now before you get worked up over how "short" the game is, keep in mind this playtester knows all the answers to all the puzzles, is running on very easy meaning he barely takes damage, and is running very fast through the game. The speed test isn't soley designed to see how fast someone can complete the game, but to test the game for bugs and make sure everything plays correctly.
The bar has been set. If you want your name in the Uncharted 3 record books you must beat three hours and eight minutes.
But don't confuse this speed run with how long the actual gameplay will take you to complete. Skyrim was recently completed in two hours and some change and fans caused a ruckus. You can't beat Skyrim in two hours, and more than likely you won't beat Uncharted 3 in three hours.