So just Linux? No Windows, no OS X? Within Windows, you'd see that Vista (unsupported by Microsoft) and Windows 7/8/8.1 which are still supported as well as OS X (10.7/10.8/10.9) whereas the last two are still supported by Apple actively; are out there in the consumer world and actively used. I'm not going to go into the BSD's and alternate OS's (think: Haiku and the like).

Mind you, I'm a Slackware user. Have been since 1996. But I now run OS X 10.9 and use VMWare to run my other OS's. I'm sure you guys can use some virtualization and test beyond a distro I've personally haven't used (although, that shouldn't really matter) and test other major OS's and versions.

Not saying it didn't happen (testing) but I'm only able to go by what's confirmed so far.

This kind of stuff is important to a wide group of possible consumers. This opens up the gate for other OS relevant questions.