I was playing DotA 2 mainly. And I play Gaias in WC3 when I'm bored or retarded.
In case they will add custom map support for DotA 2, that's a good news but who knows if there will be lots of players who will play Gaias from DotA 2. Opening DotA 2 takes some time, since it requires Steam. And I hate long updates of Steam plus the updates of DotA 2. I hate Steam if I'm asked but I'm forced because I want to play it badly.
I don't know if the graphics of DotA 2 will affect the custom maps. If it will, then, someone who wants to play Gaias from DotA 2 requires better computers. If not then it's fine. But the update will really delay the gaming. Not like WC3.
But I also agree in the idea of having Gaias in DotA 2. So I will not open WC3 anymore just to play Gaias and just click Gaias right away in DotA 2.
Well, actually, I think Zwiebelchen did try to do something similar with the release of Starcraft II, and the Hive giving mapping support for those interested in creating custom maps for Starcraft II, although it was a failure or a dead project.
More over, as LoadinG..KzHk said, it will take Gaias to a whole new graphic level. Also gaming level, as this DotA 2 custom map designing will obviously not have the same mechanics as the World Editor has.
I would personally hate to play Gaias on a different plataform besides Warcraft III. This map is actually a Warcraft III custom map. Nothing more, nothing less. But this is just my opinion.
This is not possible. It's not like I haven't thought of porting the game (as you already mentioned, I wanted to port Gaias to SC2), but the amount of work is just not worth it.
Remember that better graphics also require that all art assets would need to be redone. Also, a different platform requires a different programming language, such as complete recreation of all scripts/objects/assets.
Would've been so cool if it was possible. I actually play dota 2 and gaias a lot (actually they're the only games I play) and I'm tired of quitting dota 2, starting garena, finidng the room, and then looking for bot. Would've been much easier if it was actually ported to dota 2