One day we will live in a world where the Droid Turbo has Android 5.1. We don't right now, but this brave new world is just over the horizon. Motorola is sending out a soak test right now to users who are part of the beta group, and it could come to everyone else later this week.
It's a big jump from Android 4.4 to 5.1, so there's a huge changelog available on the Motorola support site. The highlights include device protection, priority interruptions, smart lock, and lots more.
The update has build number 23.11.38 and clocks in at 771MB. This will be the same update that is released for everyone later this week if everything goes as planned. Of course, if something isn't just right, Verizon might send it back to Motorola for retooling.