The GNOME developers announced a few days ago that Nautilus (Files), the default file manager of the GNOME desktop environment, was available for download and testing.
Nautilus 3.10 Beta 2 uses a GtkRevealer for the search bar, redundant options are no longer displayed for operations on single files, and the desktop window has been patched for newer GTK+ client side decorations.
Also, Nautilus 3.10 Beta 2 removes the double menu that appear when right-clicking on the pathbar, makes the headerbar compatible with the latest GTK+ toolkit, and the cut/copy/paste accels now work correctly. More details can be found in the official raw changelog.
Download Nautilus 3.10 Beta 2 right now from Softpedia. Remember that this is a beta version and it should NOT be installed on production machines. It is intended for testing purposes only.