Looks like the first bit of DLC will be the Beach Bum Pack. Totally free (which is pretty awesome). A few more vehicles and a few more weapons, plus some character customization stuff. Let the speculation begin.
The dune buggy is a cool addition. I wonder what weapons will be added. A giant pool noodle would be amusing, if ineffective. I'm hoping for a flamethrower or maybe a guided rocket launcher.
XBL Gamertag: JWRebholz
PSN ID: jwrebholz
...No, I'm not very creative when it comes to this sort of thing.