I hiked the main trail with a friend on 10/14 as a day hike. Started at 2am, summited at 10am, then it took us 6 hours to get back down the trail. What a gorgeous day to experience Whitney for the first time!
There were some small patches of snow/ice here and there until about Trail Camp. From Trail Camp on, there was at least 6 inches of snow. On the way up, didn't hit any slick spots until Trail Crest, which was very slick in some places. On the way down, there were slick spots from Trail Crest down to Trailside Meadow. I guess the snow had had time to melt a little and refreeze.
I passed a couple of people wearing crampons, but most people (myself included) were just using hiking shoes/boots and trekking poles. I think if it had been any slicker, I would not have felt safe without crampons/microspikes.
Here are some pics from the 99 Switchbacks, Cables and Trail Crest:
