This is the best promotional video about arma they made so far.
Explains features and content present in the game and the scale of whole project.
[youtube]ph1mm2KKSv0[/youtube]
Still, the most liked comment under that video was: "Still no rivers…" 
Darnit I was about to post this.
no sanic not u agayn!1! u went 2 fast dis time bruh, doc eckmann is gonna shreck u now.