You will need basic snow skills, ice axe, crampons and some additional warmies. Microspikes will help with the trailwalking parts if there any extended ice...I generally carry both crampons and Microspikes on winter trips.
The chances of the trail being open above cables is just above nil...which means there is a chance, but there is still the angled ice as you approach Mt. Whitney.
See my pictures of a May 2007 trip, which can be accessed through the links below. The conditions in 2007 are similar to this year.
