Now, this is an actual policy proposal spoken from the lips of Mitt himself. Voters will definitely feel more concerned about things like this than anything Hillary Rosen might say.
But they clearly don't. There's been much more discussion of Rosen's comment than this particular incidence of flip-flopping, pretty much everywhere. Will the flip-flopping, all taken together, be a bigger factor in the campaign than Rosen's comment? Yes. But Rosen's comment is likely to actually do Romney some real, albeit short-term good.