The Pen Display 24 does not have touch. When our product team was interviewing artists and designers, questing them about their top five "likes" and "dislikes" with current Pen Displays, one of the top five "dislikes" was touch.
They described how palm rejection was an issue, and touch was just not worth having at this time as a lot of applications currently do not natively support touch.
In our desire to produce a high-end display while keeping costs down, leaving touch out at this time made sense.
Please let Xencelabs know what you think. You can email your feature request and comments to CustomerCare@Xencelabs.com.