The fact that it's 2011 and only just now is MacRuby moving to git is a good reminder that getting stuff done doesn't require all the new shiny tools, and other bleeding edge accouterments.
Edit: my point was that sometimes keeping your focus on your problem, not your tools, yields the most gains.
I don't think this is so much about SVN vs Git, I think it's more about bringing MacRuby development to where the center of Ruby development attention is.
More people will click around new source commits and become inspired to make their own contributions.
Edit: my point was that sometimes keeping your focus on your problem, not your tools, yields the most gains.