Things to bear in mind about the game given the time constraints and the reuse of Rocksteady's modified Unreal Engine:
It's running on the same engine as Arkham City and will probably look and feel about the same. (probably why they chose another winter setting so they wouldn't have to mess with weather effects)
The outdoor areas are probably going to take place in a lot of the same areas and settings that Arkham City did as they don't have the time to create entirely knew sections.
It's probably going to have similar tech and not introduce too many new gadgets
Textures are probably going to be the same and we'll see a lot of reused assets
It's probably not going to have any or very very few (like 1) playable characters besides Batman
Now I'm not saying that any of these indicate a bad game, just that given the short amount of turnover and the low level of innovation that Warner Bros. Montreal would be capable of in this timeframe, I'd say that it will be very similar to Arkham City as far as gameplay elements go. Note that these are all assumptions I'm making based on my own thoughts and opinions and I'd be very happy to be proven wrong on a number of them.
@cobra88king8: "It's probably not going to have any or very very few (like 1) playable character besides Batman"
I hope we get to play as either Nightwing or Robin in the story mode (don't think it will happen simply because the game is titled "Batman")