Touchscreens use a capacitive system that allows them to "feel" the electric charge in the user's fingertips. Wearing normal gloves shields that charge from the sensors in the touchscreen.
The solution? "Touch Gloves" manufactured with a special textile covering the fingertips that allows the body's electric field free access to your tablet's touchscreen.
Here's a video from DigInfo that shows Touch Gloves in action at the Show:
Prepare to pay 1,700 yen (about $20.50) for the patterned Touch Gloves and just 1,500 yen (about $18.00) for the plain ones. (via Japan Probe and DigInfo)