Definitely a big shake up in my niche which started on Monday in a small way and escalated through Tuesday and Wednesday. Looks like the push we see from time to time which usually ends up with most of those new arrivals dropping away, eventually (usually within a few weeks).
Generally seems to be smaller sites, end suppliers. It's peak season for my niche so they'll be very happy right now, especially with just over a week to go before Christmas and the last minute panic shopping now in full swing.
Also seeing boosts for sites that are not big names as such but have been rising over the past few months at each Panda.
It seems to have settled down now so hopefully Google is now onto the sifting process and we'll see a few fall away (quickly hopefully).