Nomad Expert Technician System - MSRP $3995 - w/ built in wifi, running Windows CE, 800x600px 60Hz, monochrome red (specs). I'll break my piggy bank open as soon as the color version hits.
Lots of interesting hardware at affordable prices coming down the pipe. (See also this Forbes article which lists a number of other products: Wearable Wireless Displays Are In Sight).