add more guns that aren't extremely pricey
a lot of the new weapons are very cool to look at and make very nice fireworks, but honestly most people will never make it to level 20 to purchase something like that. it would be cool to have guns that have different looks and shooting styles, but dont pack as big a punch as the big ones. these would be guns for the level 5 gamer that does't have the time to get above that level. I.E. a cool looking machine gun that has higher accuracy but lower damage, a splatergun-shotgun mix, cannon's with high recoil, but low damage, so you can rocket jump, a less pricey chaingun, dual pistols and maybe even a few fun weapons like a rainbow particle lance style nyan cat sniper!
it would be very fun to have a new mix of guns for the noobs who can never hope to shoot a particle lance unless it's on the dummies in the training room.