[telemachos]

I may be confused myself, but I think he's doing what's described in the first example here: http://learn.github.com/p/rebasing.html (checkout a feature branch, rebase master onto it, then go back to master and merge in the branch - it gives a more linear-looking history which many people prefer).

If I'm right the point of the tip is just to simplify this set of steps into a one-liner (which would help if you did this rebase and merge often).

In any case, I'm pretty sure that this is separate from squashing all the commits on the feature branch.