I have raided as BM through all of Cataclysm and while my DPS was lower than several SV hunters, I still surprised a lot of people with the amount of DPS I was pulling (Usually in the top 2 dps on DS Normal 10).

As for Beast Mastery versus Marksmanship, I think – and I say this as a BM fan since vanilla, so I acknowledge my own bias – BM fans are usually off in our own little world. :) BM is generally less like either of the other specs in play than they are from each other. Not that Marksmanship lacks an identity in play, at all. But BM is loaded up with eccentric distinctive features, and those of us who like them spend our time trading info with each other, trying out things, and pushing far beyond the bounds of sense so that we can do whatever’s at hand the way we like it.

The other thing I think may have hampered Marksmanship is a simple fact: Steady Shot feels long and draggy, when you’ve been spending a lot of time relying on Cobra Shot for focus regeneration.

The moon was removed due to a skybox glitch that wasn’t resolved, until recently.

Over time word spreads and more and more hunters switch to what is “known” as the top spec, which usually widens the gap.

I do think the 4.3 gap is interesting — my best guess here is that the developers were busy working on MoP and as long as hunters had a viable spec, they weren’t as worried with fine tuning.