I was browsing the ArmA gamespot forums and I found recent posts by Placebo confirming that online distribution will be there for ArmA.
Link to posts on gamespot forums.

Placebo
Quote Originally Posted by [b
Quote[/b] ]Forgive the c&p but my form answer to questions about releases in currently unsigned regions:

Due to us being unable to find a global publisher we're having to sign region by region, so far signed regions are: Czech Republic, Slovakia, Poland, Russia and Germany. Obviously we hope to sign to a publisher for every region so that ArmA can be distributed in box form onto shelves in retail game stores, but we will also be arranging for ArmA to be distributed digitally online so that people who choose to can pay online and then download ArmA direct to their PC.

Current announced release dates are:

Austria 30/11/06
Czech Republic 10/11/06
Germany 30/11/06
Poland 10/11/06
Switzerland 30/11/06
Slovakia 10/11/06
Placebo
Quote Originally Posted by [b
Quote[/b] ]pjc1506 wrote:
Will they be in English as well as country language?


My guess would be (I'll need to confirm later) that the digital version will be available in all languages covered by the retail agreements, so yes English as well as other languages such as Russian, Czech, Polish etc. will be available in the downloadable version, but note that has to be confirmed when we announce details of the online distribution system.