Making branching and specially merging easier is something really interesting.

We're making a big effort on visualization too, as you can see in the following screencasts:

http://www.plasticscm.com/demos/blog_branching/blog_branching.htm

http://codicesoftware.blogspot.com/2009/03/merge-without-fear.html

I love the ideas around branch hierarchies made visible, good to see your progress too.