next-minor was a branch created by norman for Noel (and other next-minor supporters). Noel never used it, so it can be safely removed.
v2.3 is the current 2.3 branch that should be used if we'll ever make a 2.3.2
the old folder has been created by me to better identify "dead" branches. Most of them was "tags", some are simply experiments. None of them will ever be needed to make a future release so I'd like to not have them in the main "branches". So I'm against moving them back to their original place
Long ago we agreed that James should have at most 2 main code lines: trunk and stable-branch. They currently are trunk and branches/v2.3