I chose this date to be inline with the paper submission deadline, but it might be a little soon to get enough submissions.  I know there is a hard deadline for scheduling the conference that we would need to meet if we're going to schedule a panel related to this, but we probably don't need as much time for judging this as for paper reviewing.  What if we pushed this back two weeks to April 3.  I should probably have a good idea from the submissions whether a panel would be appropriate almost immediately, giving plenty of leadtime before the schedule goes out on May 1.  (But I don't know the intricacies of other schedule points, so let me know).