Most of the info here is taken from this Gizmodo article on the Fujitsu FLEPia color ebook, plus a few cut and pastes from other sites. As the Fujitsu post only seems to be in Japanese people are translating it with varying degrees of accuracy.
Resolution: 768x1024 (XGA)
Colors: 8 or 4,096 (depending on the mode; 8 colors refresh in 2s; 4,096 colors refresh in 10s)
Size: 210x304x12mm (A4), 158x240x12mm (A5)
Weight: 480g (A4), 320g (A5)
Body colors: White pearl, pink pearl, silver
Features: Touch panel, scroll button, six function buttons
OS: MS Windows CE5.0
CPU: Intel XScale
Connectivity: WiFi 802.11b/g , SD Card, USB 2.0
Stereo speaker built-in, head phone connector
Lithium polymer battery with 50 hours run time.
Confusion over pricing abounds. Anything between $12,685 (A5) and $21,137 (A4) for each of first 10 samples, or for first ten samples.
Someone who seems to speak Japanese states on Engadget “they plan to produce just 10,000 - 100,000 units in 2008 and start shipping worldwide up to a million pieces in 2009 with prices of about $310 for the small unit and $500 for the large size.”
$310 would undercut the Sony eReader slightly for A5 size, although this is color, lower battery life, etc.
I still haven't seen any mention of where the display technology is coming from, and maybe it's Fujitsu's own.