It seems to go like this:
1) They bought it with a purpose in mind but it didn't work quite as well as they were hoping (khan academy, mapping, general use, recipes in kitchen, streaming video).
2) The games last a while but they are mainly novelty rather than immersive or lasting so it's back to the XBox.
3) then the web browsing gets frustrating as streaming video is choppy over WiFi and impossible over 3G and "what do you mean flash or java doesn't work" - I can't play facebook pool.
4) then the keyboard becomes frustrating when they try and do real work because it's not tactile.
5) then they switch back to their laptop when they have to do something like mail merge.
6) then the ipad goes in a drawer, followed by ebay about 2 months after they find it again.
I've seen this so many times across about 12 ipad owners now. 20% "software dev". 40% "tech enthusiasts". 40% "joe average".
Bear in mind this is just my observation.