"Con Man centers on the post-show life of Wray Nerely (Alan Tudyk)* the co-star of “Spectrum,” a sci-fi series, which was canceled before its time and went on to become a cult classic beloved by fans. Wray’s good friend, Jack Moore (Nathan Fillion**) starred as the series Captain and has gone on to become a major celebrity, while Wray (Tudyk) hasn’t found his desired level of stardom. Wray is the begrudging guest of sci-fi conventions, comic book store appearances, and different pop culture events; however, everything is not as it seems from the outside. The series will explore these events and all the weird and crazy things that happen to them along the way."
* Hoban "Wash" Washburne in Firefly and Serenity ** Captain Malcolm Reynolds
Wikipedia says "Gina Torres and Sean Maher, both also Firefly stars, as well as Amy Acker, James Gunn, Seth Green, and Felicia Day will guest star."
So in other words it's the big Firefly / Angel reunion web show, and looks like it might be good fun. Unfortunately it's pay to view, so I think I'm going to wait to see if it comes out on DVD or something.