This news is late, but you can download the DEMO now.
The original, Operation Flashpoint, was my 2nd favorite game of all time.
#1 would be Neverwinter Nights playing Persistent Worlds I DMed.
#2 would be Operation Flashpoint playing on 10sq kilometer islands, getting in any vehicle, land, sea or air based, and having no "special toughness" ... bullets KILLED. And the AI couldn't tell who you were. You were just another soldier. Plus the Editor that was a snap to use made for GREAT fun. Neverwinter Nights had the whole editor thing going too.
Edit: Sucker's out in Europe. Here's a great review.