I dunno, if you have a gamebattles.com account I think it might be easy to setup a few clan battles against other clans. I think it would be fun to do a few times but yeah for the most part there isn't really any point to it.
The cool thing about Killzone2 is that your clan has a certain amount of "respect" and when you play against another clan you bet on "respect" and the winner gets all the points that each clan bet. SO when killzone2 rolls around (feb 27) I think clan battles will be relevant and meaningful, but as Resistance2 goes I could care less.