...a new operating system.
Here's how I think about 32 vs. 64 bit: supporting both 32 and 64 bit ABIs in X-Plane is like supporting Mac and Windows. It means a little bit more work for programmers to cover more executable types but it lets users get more out of X-Plane and add-ons on a wider variety of hardware.
We're not switch from 32 to 64-bit. We're adding 64-bit native execution to our list of supported configurations. (Linux nerds have been asking us for this for years! 🙂
So I view the question of "when will my add-ons support 64-bit" as similar to "when will they support a different OS." It will come with time, but no one is dropping the existing setup.
Developers don't have the choice to pick 32 or 64 bits; the question is whether to extend support to 64 bits.
Did any plugin developers drop Windows support when they ported their plugins to Linux? I am guessing no. And I am guessing that 64-bits will be the same way.
This is already covered in the X-Plane 64-bit FAQ, but at a minimum we will maintain 32-bit support all the way through the v10 run. My guess is 32-bits will be around for the next major version too, but we'll figure out those system requirements when the time comes.
BTW: beta 2 is out. Mac users, you have keyboards and mice again. (The bug only happened when you start the sim in full-screen mode.) Windows users, no spinning balls. And GeForce 200 users, your shaders compile. So at a minimum most of the face-palm bugs from beta 1 are fixed.