In v0.1.2 release:

• Miner performance improvement. This release includes several miner performance improvements, which have also been incorporated into several miners on the market. The official client is not expected to be competitive with market solutions, so serious miners should explore the current best performing miners on the market.
• chainsperday estimate is included in getmininginfo output. This stat is experimental so it should not be taken as an accurate estimate of prime chain rate of the miner.
• listprimerecords command for users to check all record primechains in Primecoin network.
• Miscellaneous gui and bug fixes.

This release is not mandatory.

Upgrade Instructions:

• Backup wallet and take note of balance.
• Uninstall previous version.
• Set up the new version v0.1.2.
• Start up primecoin and check wallet balance.

Contributors to the release:

David L. Unger
geeknik
joebauers
mikaelh
Sunny King

Cheers!

Update: Windows+Linux builds ready at https://sourceforge.net/projects/primecoin/files/