I'm in the insider program. I have my raspberry pi2. but there are several options for downloads. x86 vs 64 bit, cpu vs phone. but nothing says arm support. and all of them are 3GB + downloads. I chose x64 for phone, and hope that is right. Anyone know for sure?
I chose x64 for phone
Nope. The pi is not an x86-64 machine. Microsoft has not released a version for the pi yet, but has expressed the intention of doing so. [Later: They have now, follow that same link.]
In other words, you will just have to wait. Note there will likely not be a GUI desktop; it will be some sort of headless "embedded" OS.
To get it IN THE FUTURE, sign up here: https://www.windowsondevices.com/signup.aspx
The actual announcement page is here: https://dev.windows.com/en-us/featured/raspberrypi2support
The preview image and workaround can be founded in this pre release site: http://ms-iot.github.io/content/win10/SetupRPI.htm
There you can download the Windows 10 image for Raspberry pi 2 on https://connect.microsoft.com/windowsembeddediot/SelfNomination.aspx?ProgramID=8558