Indian Game -- Pawn Push Variation

So, I just ran into this freaky little variation.  Does the "Indian Pawn Push" opening have a following?  What are its strengths and weaknesses?  I tried to look some info up on line since its not in my books but didn't find anything. 

Furthermore, it seems like 2. ...c5 is the popular second move by Black, but I played 2. ...d6.  Nobody seems to like ...d6, however.  What is wrong with it?

I'll leave you a .pgn to illustrate what I'm talking about.  Any help would be greatly appreciated since this is not something I've encountered and there is nothing in my print library on it.

Aaaaaaa, helmet heads!!!

spitoons.

Weaknesses? Do you have to ask? White wastes a move on another pawn push that really doesn't help him control the center. He's behind in development and doesn't hold d4 any more. He's "out of book" for what that's worth. But it can't be good. 2...c6, e6 or g6 are recommended, not c5. There's no point to c5, since there is nothing left on d4 to attack.

I suppose I should consider them a four-handed tribute to Unca Conq...but unfortunately I find that I'm not able to.

c5 grabs the centre before counterattacking the advanced d-pawn.

And thus transposes into a normal Benoni instead of maybe trying for something more direct.