You might check to see which version of SuperDisk. A few months ago (maybe around the first of the year), imation updated the SuperDisk mechanism and these might be the old revision and someone is trying to get rid of them. The new version is said to be twice as fast.
I have one of the newer ones and although I didn't have one of the old ones, the new one seems to be pretty fast, especially compared to a Zip drive.
As for another revision, I haven't seen any news indicating it, but USB 2 is on the horizon, so many peripheral companies may be getting ready for that by dumping their older models.