I'd start out first by hoping you didn't spoil it for anyone. Ha. *Spoilers* in the title would have been good but oh well.
Either way. Yes, there is going to be a GoW3. They had already announced that before GoW2 even came out. Not to mention the little spoiler at the very end of GoW2. There definitely will be a third installment. I don't know what the plot will be but I definitely can't wait.
I'm guessing now that humanity is scattered even further with no safe havens or anything, the fighting will go back underground again. I really don't know what they'll do from here.
A1C Peck