I suspect a session by you on gdc would generate a lot of interest. ditto for David on ldc.
Me and David had a chat and kinda came a little thin on material to discuss beyond maybe a 10 minute mark. :-)
I have been collecting a lot of thoughts from what has already been done to port of D to ARM. And when I get the Epiphany board through the post I intend to port D to that too. Maybe a talk on the trials and errors for porting D.
For those who have heard of Parallela, will know that Epiphany is a chip that has been designed ground up for parallel computing. Would be interesting to see how parallel computing in D scales/fairs in comparison to the current state of parallel computing in D for x86. If there is a notable difference worth talking about, that could be another alternative.