I'm working on a case to house the Pi + PiBus interface, a hard disk and a USB hub. I'm currently looking for some suitable panel mounted connectors. It's taking a while though as I don't have much spare time at the moment.
The case is based on a Hammond Enclosure, part no. 1455ZT2201 from Farnell. It's a great looking case and not over priced at around £24 +vat. It's made from aluminium so should help with heat dissipation. I'm also going to design a simple temperature controlled fan that will be independent of the Pi.
All my designs are done using Google SketchUp, so when it's all done I'll try to post the design or email it out upon request.
Another development is to add some of the more useful XBMC plugins to control the phone and add OBC functions.
A question for Pete: Does the Pi have access to the iBus or is it just AT micro that controls it? If the Pi has this access then there should be no reason for the plugins not to work.
I have been asked by ccfj1 to build his PiBus board, if anyone else in the UK wants an assembly service I'd be happy to build the boards.