At this point the only potential I see for a viable alternative to Windows and Mac on the desktop is ChromeOS/Android, and that's still not quite where it needs to be yet.
I like that Chromebooks and Android Tablets can be under $300 or $200 or even $99 because they don't have to pay Microsoft a Windows tax because they don't use Windows. My Aunt Peggy gets confused with them and we have to put her back into a Windows machine because a Mac costs too much for her. We tried Linux Mint for her, but she got confused on it.
