The atmosphere that can be created could be breath-taking, with all of the improvements I can really expect the most ferocious and brilliant battles taking place in the most beautiful of settings. It wasn't until Operation Flashpoint was released that that important element was introduced, and to me it was the freedom to do just about anything that first caught my attention. There was always an element missing from each of those games, though. I've been an avid WWII gamer since I was young, whether it was an Turn/Real-Time Strategy, a simulator like Panzer Commander or Air Warrior (for those who still remember), or story-line based like Medal of Honor and Call of Duty I've played just about most of them. Whether it would be armor or planes, or something minor like a small unit/weapon pack, I would absolutely love it.
I personally am most interested in anything relating to World War Two being created for Armed Assault.