Personally, I think a Telltale Batman game has alot of potential to it.
Yeah, the Batman Arkham series already does a good job giving us a good experience of what it would be like to use Batman's skills and gadgets to do what he does best, but I think a Telltale Batman game can show us what it would be like to be Batman on a psychological level.
Think about it, Batman's been written and interpreted in over a hundred different ways, with different incarnations reacting to different scenarios in different ways. And a Telltale Batman game can give us the opportunity to ask ourselves "What kind of Batman would we be?"
The article also seems to imply we'll be playing out of the cowl as Bruce Wayne as well, which can make for some dynamic interactive storytelling as we players would be balancing the seemingly carefree billionaire lifestyle Bruce Wayne is publicly known for with Batman's reputation as a feared vigilante and a skilled detective. So the game will be asking us how well we'd fair psychologically and socially as being both Bruce Wayne and Batman.