I read somewhere that it could only be used for gaelic and scottish sites, which is a nice idea but unworkable.
Nevertheless, it's a case of "me too!". The fact is that .cat was set up to represent Catalan culture, then why can't .sco be used for scottish domain names (and then, as temi said, us Welsh would want one with .cym, and so on and so forth).
I think it will happen, purely because .cat domains are out there. Personally I think it's another way for domain registrants to make money (I read that .cat was pushed through by a Spanish domain host due to client's reluctance to us .es).
I notice nobody really has a problem with .co.uk (I certainly don't, I use them all the time). I can imagine it'll be used for people who are overly patriotic and domain squatters (like with .asia).
That being said, I would probably get a few .cym's if they come on the market
