The new quarterly grading special for 4th quarter 2008 has been announced on the PCGS website. They will grade any coin bearing the image of a US president, with a declared maximum value of $1000.
So, that would include Lincoln cents,
Jefferson nickels,
Roosevelt dimes,
Washington quarters (including all the statehood types),
Kennedy halves, and
Ike dollars. The new president dollar coins would of course be covered, plus assorted commemorative coins.
I do have some early proof nickels that might look good in PCGS plastic. I'm planning to put a submission together anyway, so maybe I'll sneak in an extra coin for the special.