Oblate - yes, disk - no. In order to achieve any 'extreme' shapes, the spin rate would need to exceed the spin barrier. Throwing off mass, in general, will cause the objects rotation to slow (yes there may be exceptions). Also note that YORP can spin up - but it can also have the opposite effect.
Have a look at this:
http://www.socastrosci.org/videos/harris.wmv
Its a presentation made by Dr Alan Harris at the 2010 SAS symposium. For those interested in Asteroid science within the reach of amateurs, I recommend looking at this presentation as well:
http://www.socastrosci.org/videos/Buchheim.wmv
Cheers