If you're still able to go the following weekend as you wrote above, and only a few inches of snow falls, as the NOAA (more reliable) forecasts predict, then crampons and ice axes will be useless, but microspikes might be just the ticket.
Later in winter, and in springtime, after we really do get those 21" of snow, then using those winter technical gear is highly recommended. When there is only a minor amount of snow (as we have so far), microspikes (or just good hiking boots) will do just fine.
So far, the Mt Whitney Main Trail isn't quite as treacherous as the icy conditions in the SoCal peaks last winter.
