Redmond is on a roll...or not. Windows 10 insiders on the Fast ring received build 10158 late Monday afternoon. It was immediately followed up with build 10159, which dropped late Tuesday afternoon. The sounds of "meh" can now be heard ringing throughout the testing kingdom.
As best I can tell -- and I've beaten on it -- the only visible difference between build 10159 and build 10158 is the new Hero wallpaper. Frankly, I've been trying to forget the Hero wallpaper, but if you're so inclined you can see the official video here.
Gone are the days when a guy driving through Sonoma County could snap a Bliss-full picture that would launch the XP world. Now we have a design director in San Francisco working with a team using "blasting lasers, pumping smoke machines, colored filters, and falling crystal dust."
If you upgrade to build 10159, realize that all of your old settings persist, which means Hero won't be your wallpaper/lock screen/background unless you change it manually (Start > Settings > Personalization > Background > choose Picture, then click on the Hero). New accounts will get the picture automatically.
If you can find any other changes between 10159 and 10158, hit me in the comments!