Wave Improvements

Wave improvements are sometimes announced but I think most changes are not. In the latter category, earlier this week I noticed that waves are loading significantly faster, perhaps as much as two times faster. When I first started using Wave, one annoyance was that Ctrl-Z (undo) did not work. A while later, I discovered by accident that this feature had been added. I've now subscribed to the blog I linked above, but I wonder if they mention the more subtle changes there. If someone knows of a detailed change log, let me know.