Here is a link to A New Jossverse Event. The event is at 'Thistle Hotel Heathrow' UK from 30th October 2009 - 1st November 2009. The first guest announced is Nicholas Brendon from buffy....more to be announce soon!
This is from TVguide.com, a nice little 5 min interview in which Joss talks alittle about Doctor Horrible, a mention of Buffy, some Sarah and Dollhouse.