While I fully expected a major new beta build of Windows 10 to arrive in time for the Build conference -- which starts next Wednesday -- I didn't expect to see anything earlier. Build 10061 hit yesterday afternoon, and it has some very significant surprises.
It isn't a quantum-leap improvement, but some of the pieces that have been sorely missing suddenly made a very solid appearance. In particular, the new Mail and Calendar apps (which some people are calling "Outlook" and "Outlook Calendar," for no reason I can discern) may well be the best mail programs Microsoft has ever distributed with Windows. I know, I know. Damning with faint praise.
There's a handful of additional worthwhile changes, and a whole bunch of little ones.
If you want all of the details, your best starting point is the Windows changelog maintained by studio384.be. They do a glorious job of nailing every nit in every nook and cranny.
On the other hand, if you want to see the bigger picture, through the eyes of an unrepentant mouse-and-keyboard guy, you might want to look at my Where Windows 10 stands right now post, newly updated for build 10061.
Warning: I've found build 10061 to be quite unstable. That's par for the course for beta software, but you should think twice about installing it on anything but a test machine.
Who knows? Maybe will get another build for Build.