Woo, Got a B3 last night, hand delivered no less :)
Once it's powered up & tested, projects are:

Stick it in the EMC chamber for a quick sniff, see if it's evil or  
conveniently quiet.
Probe around the SDRAM, confirm we've got some margins and not too much  
bus noise.
Build a baseboard for logic analyser breakout, and maybe some other stuff
Start cranking out FPGA code for fun projects...

For the baseboard, I'm tempted to try out the open tools that look  
tantalisingly almost useful. Any experience / advice?

Steve