I never played this back in the day, or even looked at the books, but I always thought it sounded kinda cool. I think it sounds even cooler now, so I had a look on ebay. Luck was on my side, and I now have a very cheap copy of the books winging their way to me (albeit without the box -- which I'm not particularly bothered about).
I'm even thinking about running a Spelljammer game at the local con here in Berlin this year. Would be fun to crack out the proper AD&D 2e books again :)
Anyone got any experience / memories of Spelljammer they'd like to share? It's not something I hear mentioned very often...