Rumors have swirled for decades that the footage might exist somewhere…

17 Minutes of Lost ‘2001: A Space Odyssey’ Footage Found

In short: footage was trimmed after the premiere by Kubrick, who felt that the 17 minutes slowed the pacing of the flick. From the brief descriptions of the bits cut… yeah, they actually seem pretty dull, likely to add little to the story. There’s no interest in recutting the footage back into the movie to make a new “directors cut” or some such, but a lot of hope that it’ll show up on a future Blu Ray release. The footage was found in a vault in a Kansas salt mine, and is apparently in pristine condition.