This guy doesn't agree. He can type faster than "Word" on RT can register. He was told to update "Office." Here's the process:
1 Head to the Control Panel version of Windows Update, not the Metro-accessible version that you use for more everyday settings changes.
2 Fire up a search for ?Windows Update,? and select ?Install optional updates,? instead of ?Windows Update? from the list of results.
3 If no updates are available, have the device run a check. If there are, then get going right away. The update is titled ?Update for Microsoft Office Home & Student 201[3] RT Preview.?
4 Select it, and install.
5 Reboot.
Why I?m Returning My Microsoft Surface RT | Brent Ozar
But he's just a "hater," right? SURFACE IS PERFECT!
In short, like a lot of other things in Windows 8, Metro and the desktop version of the OS are almost completely unattached, and you have to update Office just like on older versions of Windows. Completely half-assed implementation. Just slap the touch UI on top of Windows 7, and force everyone to use it.