Don't know about that. (Would love more information because we host a number co.cc sites) They do have a clause that you;re only allowed a single domain though and they've caught a few folks with that. If it's a personal site, it's free. If it's business, you have to pay after the first year. At least that's how I read it.
it's a subdomain. i would rather choose a real 2nd level name. this would be really yours. take a .com or, if you're in little budget, an .info now at 1.99 @ name.com and 2.98 at namecheap.com
Some lucky rich guy was able to snag "co" when the registration for .cc went live, and is selling the rights to rent a subdomain off of the extension. It looks legit because other ccTLDs use "co.whatever" as an official extension, like co.uk, co.nz, co.in and a few others. This one isn't official, though, and you can lose it at any given moment because the guy who owns co.cc is in total control.
One of my friend used .co.cc domain and for the first month its free and its quite natural and its really good for newbie developers. who want to learn something.