Cool! That's a darned good lens and was quite amazing when it was introduced (1989).... It's not a USM lens, if memory serves... But not sure it even needs to be. Ultrawides usually don't need to move focusing elements very far, so often can be plenty fast without USM. Ultimately, the 17-35/2.8L replaced it in 1996. Then Canon replaced that with two lenses: 17-40/4L (2003) and 16-35/2.8 (2001). Then they replaced the latter with the current 16-35/2.8L II (2007).
Like some others have said, I'd probably keep it for nostalgia's sake if nothing else.
In fact a few years ago my Dad gave me his old cameras...
Still have them and have no plans to sell them, no matter what they're worth! They need new shutters and I'll have that done sometime so I can occasionally run a roll of film through.