Valve Sued over DOTA trademark.

Just based on their stance on their claim on the dota trademark they have already lost the case.

Blizzard is just a bunch of greedy bastards

Link is dead.

Only way I can see Blizzard prevailing is if there's something in the Warcraft III license agreement that states any user-modified content within WC3 becomes Blizzard property.
And if that does go down... that throws legal strangeness into the modding community for all games. :-\
"I am not a lawyer"

The only surprise here for me is that it didn't happen sooner.

Article seems to have been removed from the site; here's the official document: http://ttabvue.uspto.gov/ttabvue/v?pno=91202572&pty=OPP&eno=1

I haven't read over all of it, but from what I can tell, Blizzard is only opposing Valve's attempt to trademark the name. They're not saying that they own "Dota". They're just defending their right to use the name. If Blizzard wins (and I'd have a hard time imagining them not), it wouldn't mean that Valve has to rename "Dota 2", but it would mean that Blizzard could use the name "Blizzard Dota" for their upcoming game.