MPQKit 1.0b2 contains an astounding amount of bug fixes and improvements. The major highlights include quad architecture support (PowerPC, i386, PowerPC 64 and EM64T), a new strong digital signature public key for Starcraft maps and a much better mechanism to represent files pending addition.
Download MPQKit 1.0b2. More information on the project is available on the MPQKit project page and on the MPQKit development wiki.