Thanks for putting up the Iowa link -- I can't believe I was so lazy as to not take the five seconds to find it again. Anyway, I think making multi-sampled instruments from that collection, while possible, would be a massive task. The samples themselves are not always in tune, they need to be normalized and trimmed properly (and looped), the attacks tend to be different, etc. By the way, this isn't meant to be overly critical, I think the Iowa people did us all a wonderful service by making these available and I use them frequently. I'm just not sure they were thinking about people making soundfonts, etc. from them in 1997(?). I think the reeds are pretty good.
Jojo -- you're right, the Waveworld collection is great, too. When I use those, I usually use Audacity to find the pitch and tune them, though, just because they aren't always labeled very well.
Does anyone have any idea if it's OK to post a mod with commercial samples? Obviously you can tell people in the comments, sample titles, etc. not to rip them, but I wouldn't want to get in trouble for spreading copyrighted samples all over the web.