So far I have found no distribution that has really been designed for a tablet. Netbook remix, as I've discovered, is little more than Ubuntu with big icons on the desktop. This is next to useless if you haven't a keyboard, nor fingers that come to a fine point.
So a rapid zoom function is clearly necessary, as the folks at Apple (blecchh) and Google have discovered, to really get good use out of a touchscreen.
My touchscreen: Egalax.