I have the same shield as shown in first post of this thread.
Bought mine from Sparkfun, ordered 11 July 2011, Sparkfun part DEV-09026
At 24 Aug 2011 Sparkfun were still showing that on their site, and had a lot of specific information about the board and its use. No mention of POE.
They speak of it as "the latest revision"... and they are (again) out of stock on this item.
SHAME ON SOMEBODY... no board should be produced without a clear version id somewhere in the silkscreen...
But it does work nicely! At least with my UNO, running my little ArduServer demo which has two buttons: "LED On" / "LED Off", a label to tell the user what light level is being seen on the light sensors the LED shines on, and code to connect my server to a service which logs visits, displays where visits have come from on a spinning globe from RevolverMaps.com.
See demo at....http://www.mon277rr.dyndns.org:81/
Back to the mystery board...
It would be "nice" if the good people at the Arduino "home office" would update...http://arduino.cc/en/Main/ArduinoBoardEthernet
... put a picture there of the version-less board, give it a version ID so that we can have sensible discussions about what it can and cannot do.
If there's room in the silkscreen for "Zero carbon footprint"... in two languages... a claim that I find peculiar anyway, there's room for a version id.
Not impressed. Will go back to buying clones!
(It does seem to be a pretty good board, though, I will concede.)