Matt said a few relevant things that you may have not noticed before. The main thing I took out of it, which I knew, but he made a point to say it, was that Google made 665 changes to the search engine (UI and more) in 2012. So that is about two changes per day. So when people like me go to Google and say, something is up, Matt said - yea, every day we release a couple changes - so something is always up.
Here is the video, it is about 3 minutes and 10 seconds in:
Another thing he mentioned was that he loved that the portal shows examples of spam sites removed by Google in almost real time. So you can see the spam as it is removed. Going back to that, my company built a search engine for the spam sites shortly after they launched it. This would allow you to search the sites Google manually penalized so you can get a better understanding of sites they are removing. Google forced us to shut it down because they didn't want us crawling their examples and giving you an index to search through.
That being said, Google's Matt Cutts also has a video on how search works in general from 2012.
Forum discussion at Twitter.