EPTSo there are a lot of reasons why this is happening. Some people may not realize yet? Anyway DOTA 2 has/will over the next few days basical solidify itself as the #1 "competitive game" "esport" etc.
1. Smooth Transition. Dota 1 and Dota 2 are nearly identical games. Valve has also worked hard to include china in upcoming events like the gamescom tournament instead of burning bridges. This basically means it will "swallow" the older scene as it moves forward along with its history, teams, and established fans.
2. DOTA TV. It's hard to describe how huge of an impact this one feature will have on DOTA. The ability to look up any ongoing public match and observe it with optional shoutcasting support. (search parameters like team/player/hero/skill level/friend. Archives of big matches with commentary. The unique ability to watch events in full ingame resolution with shoutcasting all built directly into the main portion of the game. Can even queue up for matchmaking while watching and smoothly join a game from obsing. WITH inbuilt delay for cheat prevention. With fully dedicated servers (which also stop maphacking and make the game more secure).
3. International Support. Already have partners in China ready to roll the game out, and are including the entire world in promotional activities.
4. Proper tutorials, coaching support, guides, etc. That will actually teach you the game and even allow you to train aspects like last hitting/denying etc. Because of porting DOTA 1, all the legacy guides will still be applicable.
5. Spectator features, a huge problem domain is making games more spectator friendly in any way possible. DOTA 2 takes this to impressive levels as we will see more clearly at gamescom. ALong with replay features like a free camera and game speed fine tuning for creation of better highlight videos of matches. Group replay watching as well.
6. International Match Support, its a priority for valve that international play be as low latency and responsive as possible. Lan Support is 95% confirmed as well for smooth running events.
Basically Valve is going about this, probably with Icefrogs guidance, in just about the most perfect way you can imagine. It wont be any surprise when DOTA 2 eclipses basically all other competitive games which will be quite surprising to many people. It will be a combination of technical reasons, developer support from the top down (gabe newell himself has commented about pushing esports further with dota 2), and bringing over almost the entire existing dota 1 community.
When you quickly compare SC2 to DOTA 2 in terms of technical, developer, and community support. The only area SC2 surpasses DOTA 2 is the amazing community of teamliquid and gomtv, the other is clearly in DOTA 2s favor.
It will be a very telling sign and a "passing of the torch" this week.
Note I think SC2 sort of had a very flawed support for the first year and a half from blizzard, and it is not a knock on the competitive merit of the game, just the official support behind it.
