The Pixstone series is a new series started by Phat Company and its first release being the characters from Black Rock Shooter with Black Rock Shooter herself and Dead Master released together.
Next in line for release in this series will be characters from Touhou Project with Reimu Hakurei and Marisa Kirisame. Prototypes for the Touhou Project series can be viewed at this previous post.
Release: May 2011, 680yen each (Tax Included)
Source: Goodsmile.co, Mikatan's Blog