Personally I see it as an unnecessary step backwards.
I perform all functions either by swiping or on screen. But....I'm a hybrid, remember I started using full touchscreen way back with the iPhone 3GS so I've had a long time to get used to the absence of a trackpad.
There hasn't been one single solitary moment when I've thought to myself "gee I WISH I had a trackpad.". Copy/paste, text selection, radio buttons on surveys, fields to type into...all done effortlessly without the belt. I personally don't need it and don't want it.
Actually, I think I would resent the presence of the belt. Like an obstacle I have to go over.
But....I'll still buy it.
Posted from my awesome Q10 via CB10.