Windows 8 isn't going to be a sure-fire solution to handling Sublime Text, as the ARM version will not support the "classic" environment that allows you to run desktop applications that weren't written with Microsoft's new fancy crap.
When it comes to running Sublime Text on other OSes aside from the current ones, that IS quite the undertaking. The fact that it runs on OS X, Windows, and Linux is pretty fantastic, especially with how fast it performs on all of those platforms. The high performance indicates that Sublime Text must be coded in a very fast, modular manner that allows for efficient porting between operating systems.
This is why some open source projects bring on people to maintain a specific platform version of the software (like VLC), but this also poses a problem of consistent support across such platforms (again, VLC ran into this problem when they lost some OS X developers and couldn't quickly build the x86_64 versions of VLC for a small time).
This isn't open source, but it would be interesting if a completely torn-apart version of Sublime Text could be released in source code to see if people could make good ports to iOS, Android, etc. And evaluate the possibility of its existence on those platforms.
I'm not really asking for this, just proposing an interesting idea. I find it hard to ask for more when Sublime Text is already kicking a good amount of ass.