Last August, Congress passed into law a new provision to 49 USC 44703 that mandates that the FAA establish an electronic database to keep records of enforcement actions for the life of the pilot.

The FAA's Chief Counsel has suspended its current expunction polity pending further review - the last expunction took place on November 1, 2010. For the time being, if there is anything on your record that has not already been removed, it won't be.

Here's the FAA's FAQ on the subject:
Pilot Records Expunction Policy Changes - Frequently Asked Questions (FAQ)