With the EFI instead of a BIOS, there is no direct access to the system board.
Which means there is definitely no easy way - if there is a way at all.
Have been overclocking my Win boxes for several years. However, only did a very preliminary search regarding this right after I got my MBP. Found very little. Did find one Open Source project
rEFIt, but have not tried it. Looks like it provides some access to the EFI system, but don't know how much. Read through the forum there a little and looks like it is mainly being used by those that want to run Linux natively on their machines rather than hardware enthusiasts trying to get maximum speed from their rigs.
Think I just finally got out of my windows mentality of spending at least 25% of my computing time messing with the system, tweaking, etc.; and just started using the box I have. For an old timer it really has been a welcome change.
Note: They havn't gotten it working on the new Santa Rosa chips yet either.