Matthew in "Manor Hunt Ball"

According to this webpage, Matthew Macfadyen will be starring in a new horror film called "Manor Hunt Ball" by Stealth Media Group, with filming in the 4th quarter of 2010.  Edit: other actors involved in the project indicate filming begins March 11, 2011.

"Synopsis: A gang of local youths crash a high-class party at a country manor where they discover that the modern gentry are now hunting people instead of foxes. Running for their lives the gang must find a means of escape before they are picked off one by one."

The film also stars Rupert Penry-Jones, Blenda Blethyn and a host of other actors.

(A huge thank you to the German forum for finding and sharing the information)