^--You people need to read dates.
To repeat:
The XDA Developers' Surface RT jailbreak tool does not work with Windows 8.1 because Microsoft closed virtually all the loopholes.
The ONLY way to use the XDA jailbreak now is if you have a first generation Surface RT that is not patched to 8.1 and DISABLE WINDOWS AUTO-UPDATE (this requires a registry tweak), which likely means any further performance and bug patches will be completely unavailable to RT v1 users--and real quality of life improvements like Outlook. Of course, that's then a decision based on whether the jailbreak ARM apps are more important than whatever 8.1 brings.
Obviously, the XDA jailbreak is impossible on the Surface 2.