I just want to share this find with you that took me a lot of time to find...
If you have a remote that sends keyboard commands (like soundgraph imon) and want to take advantage of sms-style input in xbmc virtual keyboard inputs than this is what you have to do:
Find your keyboard.xml file and add (or change) the following lines:
That's it! Save and restart XBMC.
Thanks to cpt. spiff for helping me out on this one!