What would make people choose the Pegasos over a standard Wintel-box? Near inherent protection from viruses and worms, perhaps a little more stable, although I have heard good stories about XP and 2000. (That's hearsay, I'm sure you all know a friend who cursed said OSes from here to Hell and back.) That's about the only things it has going over Wintel. As for the rest: no wide selection of (lots of illegal) games, very little support for hardware which you can buy cheaply at the local store, no wide range of applications.
It *is* a nerd's toy, and never will be more than that, unless you have billions of dollars in your development and marketing bank accounts. Making it appear something which it isn't is a waste of time, money, and effort. That said, it is a pretty cool nerd's toy, though... ;-).