Open beta is a bad idea for first release of SOW. Too many things have to be kept secret until the very end. There are wankers already trying to get their greasy hands on the SOW code for one reason or another. The later this loosers come in contact with the game, the better.
For addons after BOB, once SOW engine is known to the public, maybe.
In the mean time I have a blast with the DCS A-10.
