First of all, it's too late for FSX Acceleration. The beta for Acceleration will be shut down soon, so there isn't any point in joining it. If you want to be considered for the Train Sim 2 beta, then you should use the fs_ideas e-mail alias to sell yourself to us.
We won't open a beta for FS11 for a long time so it's too early to apply for that.
When users/developers apply for any beta program we look for the following:
- How the user interacts with the community (how active in forums, how helpful they are with other users, whether or not they can logically evaluate issues without being overly emotional about it, etc)
- If they are developers of add-on products
- If an existing beta member that is particularly good is willing to recommend the user for the beta
Being a beta tester isn't an easy job. First of all it's purely on a volunteer basis with the only thing you receive being the opportunity to see product before it's released and a final copy of the software (assuming policies don't change). You must be active on the beta forums or filing bugs to stay on the beta long-term. You have to put up with some nasty bugs and will likely have to install and uninstall software rerpeatedly and remove third party add-ons.