It would be nice to see the Unity Editor working on Raspberry Pi with the Raspian Distro.
There probably isn’t enough horsepower in the RPI (or even the RPI2) for the editor to run fluidly, but I think a Unity player for the RPI2 (which has technical specs similar to mobile phones from 2012/2013) would be a reasonable effort.
Unfortunately this simply isn’t feasible. Aside from the issues of porting to a completely different platform (ARM vs x86), the fact is they’re ditching 32-bit support for the editor. Both the first and second generation Raspberry Pis are 32-bit only.
I love the Pi, it’s an awesomely fun piece of hardware…but no.
The Pi isn’t a dev box, there’s reason cross-compile toolchains exist. Even the Pi 2 is sooo much slower than my laptop when it comes to compile times.
Pi as a build target though? Maybe. At one point I could get behind that, although I’ve since found engines that make better use of the Pi hardware. It’s too much of a hobby/maker platform to make financial sense for UT to support though 
I don’t mind about the editor, but it would be great if you could deploy apps to ARM based devices.