The kernel source was just recently released and the developers at XDA immediately went to work on an overclocked kernel. They managed to get it up to 1.4 GHz, but it is not quite ready for general consumption. It is still in a preview stage which basically means it is in alpha testing. You should expect many force closes and crashes. Initial testers claim to have boosted their Quadrant score by around 400 points.
I can not recommend that you flash this kernel at this point, but if you must, then follow the source link for instructions.