I'm doing a site for a .mobi right now (not mine -- for a client). If you can get one, squat.
But don't get amazon.mobi because, yea, you'll just be asking for trouble -- not likely you'll get it tho...or any good .mobi. All the domain registrars took all the good ones already. It's their business to squat.
'Bout the only good domain name you'll get is for a new word that becomes a hit. Like if you got "google.net" before "google.com" was a hit...but that's just sheer luck. The .com for the .mobi I'm making was already taken (even tho the domain name is totally goofy) -- so if the .mobi I'm making takes off, the owner of the .com will be stoked...and it will have been 100% luck for him.