I guess the most relevant question here is whether or not we could eventually start listing Linux applications here on the site and just list a dependency as "Ubuntu for Windows" like we do with Java, Visual C++ Redist, or dotNET. That could be cool.
As someone who runs Windows inside a virtualization layer, this is less exciting than for others but certainly for Windows native users, there's a power and efficiency improvement there which is probably good. As for how this helps Microsoft, I'm not really clear; it makes sense that desktop Linux users would be more likely to run Windows 10 now since they'll have increased flexibility but how many people is that? It seems just as likely to pull development energy away from Windows APIs and push them to Linux. *shrug*
Wow, very interesting development. I hope it's not an April Fools' joke. Currently I'm in a dual-boot with Win10/Ubuntu Studio so that I can run my GNU/Linux-only graphics apps. If this comes to fruition it will certainly make life a little easier.
I've asked around a bit and still have no clue what's going on with this move but one possibility is that it has more to do with the Microsoft SONiC virtual networking effort, which I'll be honest I don't really understand. Why Microsoft is participating in software-defined networking but not selling it is just confusing.
When this happens, I would somehow love to portablize bash. I'm guessing data will be stored in system directories like %appdata% by default, which is something I would want to change.