It is really hard to find a domain name that sounds good and easy to spell. There are too many extensions for a single TLD. I am not even sure whether someone is able to get a domain name of their choice unless they can spend $1,000 or more.
Maybe Facebook will offer some unique names under fb.com domain. Because almost all successful instances on internet has their presence on FB too. At some point, people will say " enough, I going to start an FB page or group" .