It was only two extremely dry years ('12 & '13) that the switchbacks were in use by Memorial Weekend. I think it will be a week or more later this year.
While using "the chute" aka the slope west of the switchbacks, you need crampons, and an ice axe is recommended, too. Once the switchbacks open up, microspikes are helpeful since there will still be snowy sections for several more weeks, and the section at the cables can be icy. (Yet some people navigate that only with hiking shoes and a lot of care.)