We will be sending out an update today or tomorrow to all the registered entrants. Instructions for uploads will come out toward the middle of April (once we have all of our servers setup and tested).
We are planning to send out the email today. Please note, you can already submit whenever you are ready. Simply go to the Virtual Appliances Directory ( http://www.vmware.com/vmtn/appliances/directory/) and follow the directions in the "Welcome" box in the upper right corner to "Enter Challenge"