Microsoft looks to be stopping production
http://www.ubergizmo.com/2014/10/microsoft-may-stop-producing-arm-based-surface-tablets-report/
Switching to Intel based instead. Windows 10 is suppose to work on desktops, laptops, tablet and phones so it makes sense they are discontinuing.
I think it is important to point out that the Surface based on Windows RT will no longer be produced—HOWEVER, the Surface based on Intel-based processors will continue.
Windows RT-based Surfaces are only a subset of the overall Surface family.
The ARM CPU is only used for the operating system known as “Windows RT”. Surface Pro devices all run Windows 8 and Windows 8.1—not RT.