Well, its success depends on how much they allow the game to be successful. I mean the fact that they've kept it away from Harvey Smith is a great thing, but I think that Harvey was also under a lot of pressure from Eidos to make it more accessible to console gamers. He just took it a little too far.
Plus they wasted valuable time making their own engine. I think it was based on the Unreal engine but they replaced all the major modules with their own. Their engine was horrible. Tiny levels and poor performance with even the beast rigs of the day. Plus the ginormous, un-PC-like text and blurry textures. Many people made high-res texture packs and found ways to shrink the text which improved these issues, but then load times were really bad. As small as the levels were, this was not necessarily an improvement at all.
Hopefully, that doesn't happen with DX3.