Scott Chacon and Markus Feilner have introduced GitButler, a tool that changes how developers work with branches in Git: instead of working on a branch, possibly introducing changes that belong in other issues, developers can work on a cohesive codebase and split changes into lanes that make more sense in context, which can make working with git much cleaner.
diffnav gives git a syntax-highlighted display of changes in a navigable filetree, as a natural extension of git-delta. Very nicely done and potentially very useful if you're using git from the command line.
Bram Cohen, creator of BitTorrent, has released "Manyana," a version control system with a new way of tracking changes that reduces the impact of merges to something more manageable and coherent. It's only a proof-of-concept as a VCS, not a replacement of Git, but looks interesting.