Valve has sent out confirmation that the long awaited sequel to DoTA - yes, DoTA 2 is coming. Sure, Half-Life 3 isn't, but DoTA 2 is.
The official announcement is to the point, as ever with Valve and thankfully so:
"Coming to the PC & Mac in 2011, Dota 2 promises to take the unique blend of online RTS and RPG action that has made Dota popular with tens of millions of gamers and expand upon it in every way."
That's all we have for now.