OMG, they're actually charging for this? That's just adding insult to injury. They haven't addressed the horrifically low resolution textures that plagued the game, as if you look at the new screenshots they all have high texture detail for the character models and textures from 1994 for the environments. Look at this screenshot to see what I mean - all the environment textures are low resolution, overexposed, incongruent with surrounding textures and it's almost impossible to determine what material they're trying to portray.
The first thing they should have done was to release free DLC that added an actually ending to the game, which was alluded to in conversations with characters but never materialised. The second thing they should have done was to release the high resolution textures that Carmack talked about - even if they weren't much better it would have at least shown they were serious. And finally they should have released the mod tools that they said were going to be released with the game.