There is already a post about this new feature of GNOME, but I made also a video because I love it. While it just seems as a small addition, it adds tons of points in GNOME usability. In my opinion, one of the killer new features of Shell 3.12.
Overview, Arrows select Window Thumbnail, Return brings focus
UGR Ep1 | Split Views Tips | Gnome 3.11.x
UGR Ep2 | Pick The Right App From Overview | GNOME 3.10