The rumors and speculation can cease. Valve is making Dota 2, we've played it, and it's already amazing even though it's not coming out until next year. And we haven't yet laid eyes on Dota 2's biggest innovation: a radical approach to integrating the game's community back into the gameplay itself.
...I know I shouldn't be surprised they didn't announce Half-Life 2 Episode 3 but that doesn't help my level of disappointment with Valve. Still, it's great news if you love DoTA or any of it's successors/clones.