That'd be disabled with "echo 0 > /sys/devices/platform/omap2_mcspi.1/spi1.0/disable_ts"?

First I thought this could be handled as a DCEW script, then I thought it a bit further.. After disabling the touch screen, DCEW wouldn't be much use

Would work great with keyboard-shortcuts, though.

edit: Matan has also released longpress which allows changing between general/silent or general/offline profile with long press of lock slider, I think this could easily be modified to enable/disable the touch screen.