Whoever's manning the twitter account is quite responsive. I tweeted @surface regarding remapping the buttons and they replied recommending a YouTube video about remapping the top button. I replied stating that right-click and middle click on the side buttons is what's really needed, and @surface didn't respond.
It's like they refuse to acknowledge this is an issue. I don't see any Microsoft tags in this thread for sure.
Anyway, I'm holding off on buying one until they include this feature. I'd love to use a SP3 for Photoshop and Mudbox, but with only 1 mouse button on the stylus it's currently of no use.
To do something like this Microsoft depends on the OEM drivers. So it's up to Ntrig to release drivers supporting these features.