In some capacity at least.
http://badassdigest.com/2015/01/07/david-cross-confirms-mr-show-will-film-in-march/ The gist:
David Cross offered up an extra spot on Mr. Show for a backer on his kickstarter page (https://www.kickstarter.com/projects/1573560609/hits-a-film-by-david-cross), and that is functioning of essential confirmation that something is going to happen. (He's also offering to shave his beard for the show.)
Anyway, I'm excited. I loved Mr. Show, and I'll watch anything they do.