Quick update: Nemo (2.8.7) with Unity patches and without Cinnamon dependencies is now available in the WebUpd8 Nemo PPA for Ubuntu 16.04 Xenial Xerus.
For those not familiar with Nemo, this is the default Cinnamon file manager and is a Nautilus fork.
Nemo continues to provide many of the features removed from Nautilus, like the extra pane or the toggle location button, but there are some other changes as well, like a customizable toolbar (you can add or remove the up/refresh/search/etc icons), built-in "Open as root", "Open in terminal" and "Set as wallpaper" context menu items and much more.
Besides making Nemo available for Ubuntu 16.04 in the WebUpd8 Nemo PPA, I also updated it to the latest 2.8.7 version for Ubuntu 14.04 and 15.10.
A while back, I updated Nemo to version 2.8.6 however, many users complained about frequent crashes, so I downgraded it to version 2.6.7. The the bug that caused those crashes was fixed, so I decided to update the PPA with this version.
Note: Nemo 2.8.6 is available in the official Ubuntu 16.04 repositories however, it can't be used to draw the desktop under Unity and it comes with Cinnamon dependencies.
Install Nemo with Unity patches in Ubuntu
For how to install Nemo with Unity patches in Ubuntu, see this article: Install Nemo With Unity Patches (And Without Cinnamon Dependencies) In Ubuntu
If you already have the WebUpd8 Nemo PPA added, simply update the software sources (run "sudo apt-get update") and then install the updates any way you wish (using Software Updater, command line, Synaptic or whatever). After the update is done, either kill Nemo (using the "killall nemo" command; "nemo -q" doesn't work with updates in some cases) or log out and log back in.