Let me talk a bit about DOTA2...
I will start with the graphics; they are very nice and even better in motion, Valve artists did it again. I really like the artstyle they are going there and for the veterans, it's nice to see your previous favorite DOTA heroes in HD.
The voice acting is top notch, you even have some special responses when you kill some specific hero! I can see me playing with all of them at least once just to see how they sound.
And there is a training mode with bots for these among us who are DOTA-impaired.
But even with bots, I'm having a hard time. DOTA have it own flow and you need to "get" into it. The difference between a lost fight and a sure victory isn't obvious at first and it's very easy to walk in a trap. It's a game which require you to learn it before you are able to enjoy it.
I think the game will captivate the veterans and maybe even convert some naysayers, but it's still DOTA at heart, love or hate it.