As you all know, Windows 10 is being offered as a free upgrade to qualified systems until July 29, 2016.
On clicking "Get Windows 10 app" icon in the notification area at the right-hand end of the taskbar and selecting the hamburger menu in the upper left-hand corner of the app, then selecting Check your PC (or Your PC is good to go) to see any known compatibility issues and recommended resolutions, it shows, among other things :

Apps : 0 incompatible

My PC which is a Windows 8.1 Pro machine has RMS 5.2.2 installed

If I opt to upgrade to Windows 10 Pro now, what would be the gotchas (if any)? Would I still be able to use Rho to develop for Android, Windows Mobile, Windows Phone 8.x and Win32 ?

Any insights?