Yes, me? Do I know you from somewhere? Was my attempt at a semi-troll really that see through?
Regardless, I'd like to see ArmA2 play nicely with Steam, as much as a lot of people like to flame it, it's a good service, especially if BiS recognise it.
As for Beta's being overwritten, there's a way to have separate installs for live/test games. As I said, it'd need BiS to recognise Steam as a platform.