It's hard to work out who got Marines or wanted it/didn't get it. I'm not sure if there's official stats out there.
From my class, we had:
320 attend Leatherneck
~50 or so attend MAGTF (don't worry too much about what that is since 99% of the time it won't apply to you if you actually go Marines)
...For a total of 370, not including a few other odds and ends who went on SEAL or EOD cruises and decided it wasn't for them.
-272 selected USMC. Keep in mind that a lot of people go to Leatherneck and decide it's not their thing. Rumor mill was 50-60 people were not selected for USMC who put it first, but I don't know where those numbers are from.
-268 actually commissioned as 2ndLts (drops were due to medical)
For future classes (2013+) it sounds like they're trying to make the cut before even attending Leatherneck, so a lot of this might change. Supposedly, 2013 had fewer USMC applicants than spots for the first time in years. KEEP IN MIND this doesn't mean that the Marines will just say "Oh, you have a pulse? Welcome to the Corps!" My understanding is that if they don't have the number of mids going Marine Corps they want, then they just don't have the number of mids they want. They're not going to drop standards to meet the quota...I saw this last year with air contracts.
The "going Marine from USNA" pep talk: Don't let the uncertainty dissuade you. You can make it happen. Going USMC from USNA is very doable if you work hard and don't suck. The people I know who didn't get USMC who wanted it (with extremely few exceptions) only have themselves to blame.
I can't speak for the fleet, but at TBS all Lieutenants are equally worthless. No source has a significant advantage over any other. In one sense, the Academy kids have an advantage for having put up with things that don't make sense for four years, making things that don't make sense here so much more tolerable.
I was worried about being behind the OCS and NROTC guys as far as tactics or Marine Corps knowledge since I had brain dumped Leatherneck, but I don't feel behind at all. The material is new to most of us, even most of the priors, so we're on an even playing field.
A couple OCS guys half-kidding gave me and the other Academy kids flak the first couple weeks for being a boatschooler ("Oh, they just take care of one another and don't care about anyone else"....not true...) or "not being a real Marine"
rolleyes
but they're idiots and shut up pretty quickly once we actually started training. There's still some well-intentioned (mostly) ribbing between commissioning sources 2+ months in, but that's it.
The TBS culture is very different from the Academy: if you can adapt and use what you learned at USNA to help other people out and make things run smoother, then you will be successful. If you still try to act like a midshipman as a 2ndLt....you're going to have a bad time.
Bottom line: don't be a tool and you'll do great.