After the final numbers came in (2am), what I saw was similar to what @diberry posted except the flow was constant all day and comparable to the previous 2 weeks with slight increases overall (no holiday decrease. The SERPs for keyphrases we came up short on showed our listings fell or disappeared from page one results but one or another competitor had 2-3 related pages in a row. In reverse, the SERPs for keyphrases that showed increased traffic showed us moved up considerably on page one or in a cluster of 2-3 relevant page listings the same as the competitors were. No doubt it was the algo update in progress.
Later in the morning (8am+) the SERPs are mostly normal again, only a few double or triple listings and the results are reordered a bit with a few more competitors our age or older showing up right behind or just in front. It's actually nice to see them up again and the newer sites that scraped sites (us and competitors) got bumped in most results tested but they are still there.
Compared to last two years Memorial Day Weekend (Friday Numbers):
a newer site has increased by 151% over 2011 and 440% over 2010
an older, lower quality site shows -83% from 2011 and -79% from 2010 (this was a Panda victim).
Personally, I think it's too soon to make assumptions, especially with the update hitting on a holiday. If we come out matching or ahead on the next three days it should be positive from there on out but generally speaking the algo updates have always looked good for us in the first few hours then cause a sharp drop within 24 hours.
@aristotle - we had 2 sites that linked to our newest, most popular site massively go under just about the same time that Penguin came out, 2 more lost their hosting privledges at HostGator a couple weeks after (and yes, there was an almost noticeable increase that seemed related but I'm talking about 100-200 uniques and that could just be a natural progression as that site grows and adds content). There are still about 5 more that link even worse, one 5000+ links.