My intention was to use this ARM CPU as the host, and communicate via ethernet from there. No need for a sheeva plug.
I as a noob have a questin here: As different Daugtherboards/FPGAs should be supported, would this ARM CPU program these fpgas? Or how do you do this, as nobody except the backplane knows which types of daughterboards are connected?
Additionally I want to say that I really enjoy this thread here. Thanks for everybody involved. I guess I will personally switch in read-only mode for now, as I have only slightest experience with such electronics.