I can have many OSs on my Android mobile phone just by running Teamviewer.
The phone must become some sort of mobile computer. At home/work I want to put the phone in a cradle and use it with a monitor, keyboard and mouse, just like any computer. So, the OS must be separated form the HW
I'm waiting for the day when mobile HW and SW platform will not be linked. I buy a phone and I buy the licence for the operating system i want (Android, Windows, I-something, Linux etc.)