The PCI slots on the Micronik boards were intended for a never-released bridge card. A Commodore Bridgeboard might "activate" them, but of course they'll only be usable on the PC side. It might be possible to write drivers over the bridge, like for some ISA Ethernet cards, but there's no documentation for the Micronik board and there'd probably be a tremendous bottleneck.
The Mediator isn't compatible with the Micronik busboards, and Elbox stated in their last press release that the Mediators don't provide 3.3V power so they'll be releasing an adapter.
