BFGMiner's "prime" branch seems to work, at 2000pps for me (on a system that primecoind was doing well under 100pps on, unoptimized).

It's not user friendly, and not intended to be easy to use, as it's still in development.
I'm not sure if I'm going to finish it, as I'm pretty sure Primecoin is a scamcoin - but maybe if others want to join in the development we can share the bounty?
Basically it mostly just needs cleanup at this point.