Adobe seeks testers for 64-bit Air on Linux
If you're running a 64-bit Linux distribution on your system and can pitch in with bug reports and devote some serious time to testing you can email Adobe with your particulars. While I haven't received word back from Adobe as to why Linux is their testbed of choice, it surely has something to do with the number of Linux users running x64 distributions and their willingness to experiment with pre-release software.
Update: Adobe's Matt Rozen has just emailed me a response. He says "We have seen much stronger interest from the Linux community for a 64-bit version of Adobe Air, so that has been the focus of our efforts."
Windows users will have to wait patiently. There's no news at all yet about Air and the official line on Flash is that 64-bit support won't come until the next major release.