After a weekend of play I can honestly say RESISTANCE 2 IS GONNA BE ONE OF THE BEST GAMES OF THE YEAR! I always knew it would be a good game, but my god. The co-op is seriously one of the best things i've ever played.
Lets start with the classes, there is Solider, Medic, and Spec ops.
Solider: They are your heavy hitting, damage taking tanks. Their primary weapon is a machine gun that has 200 rounds per clip. Soliders also have a secondary fire of a shiled. The best thing is, they get exp for being them. Firing on the enemy and taking damage nets exp points. How great is that? The Solider class is easy to pick up but difficult to master. I've seen some really great tanks, and I've seen AWFUL ones. This is my Second favorite class by far.
Medic: They are your healers. Their rifle deals damage to the enemy and heals your allies all in the same kinda shot(explain that to me). They have a secondary fire that heals all within the radius. Medics get exp in three great ways, hurting the enemy, healing your allies, and reviving dead allies. Now, I am probably the worst medic around(in fact, if you see my tag Kill7Me2Plenty3 and i'm a medic be worried), but I've seen some GREAT medics out there. Imo, they are the hardest class to be good at. You have to know your role and know it well. I wouldn't say I hate this class, I just hate that I suck so bad at it.
Spec Ops: This is my FAVORITE class by far(and I think I do a good job at it). They are a support class who is all about long range fire. Their primary weapon weapon is a high powered rifle with a long range scope. It is single burst but does its share of damage. Its secondary fire is what I assume to be only a electric bolt that deals damage(I'm not entirely sure). But where Spec Ops shines is their supplying of ammo. They are so valuable in battle. They will keep your tanks full of ammo, grenades, and even give the meidc's hedgehog grenades. They gain exp for damaging enemies and giving out ammo. With a good one, a tank could stay up forever(shield included) destroying all in its path. With a bad one, well, lets say mission failed shows up a lot.
In conclusion, the co-op is top notch. The board is fun and challenging. The level changes everytime you play so you don't have the same experience twice. When this game comes out, if it gets anything less than a 10 I'm going to be shocked.