We have just released a new firmware build for Meridian/P that supports the Ethernet adapter board.
The firmware includes SSL and DPWS support. You can download it here.
Please read this document before you hook up the Ethernet board as there is one issue that could let the smoke out of the Meridian/P if you do it wrong!
We have also released a new version of the standard build that fixes an application deployment issue that some people were seeing.