I was very lucky that my constitutional law professor took the 2nd amendment seriously. Indeed, 99% of con law classes taught in law schools do not cover the 2nd amendment. That being said, my con law prof was, to put it mildly, a liberal ivory tower type. Even he, said that the 2nd amendment protects an individual right. Indeed, when one of classmates tried to assert the "collective rights model" he browbeat her (academically that is) into submission and tears.
The issues that arise in the modern 2nd amendment arguments have been well fleshed out here. But perhaps I can shed some more legal light, and focus the debate. Miller is not considered good law by any well informed con law professor, nor by many federal judges. Generally it is considered to be an uncitable case (just as Korematsu is). Although technically "good law" in that it has never been overruled, it will never be cited by the sup ct, and the fact that it was, essentially, an ex-parte case makes it that much more distasteful.
As for the 9th cir, they have said, and it has become circuit law, that the 2nd amendment is indeed a collective right held by the states. Recently, however, the 5th circuit in United States v. Emerson held that the 2nd amendment is unequivocally an individual right. This is what as known as a circuit split; generally a fast track to cert to the Supremes. However, the Supremes have ducked this one--cert denials in all cases have been unanimous.
The real debate, at least in con law circles are the contours of the 2nd amendment--what does it exactly protect. All agree that the states and feds (to a lesser degree) can prohibit felons from possessing arms (note only firearms). However, can congress prohibit measdemeants from owning firearms? The answer, at least in congress' eyes is yes, google the launetberg amendment if you dont believe me--I tried to convince the fed judge i worked for to strike it down (he declined my invite). What about licensing? I think that we could look to the abortion debate and the answers there for a good analog--e.g. Casey v. planned parenthood and use the obstacles test.
Oh, as for the text of the amendment. A militia by both federal and state law is every able bodied man between he ages of 18 and 45 (sometimes older) every state in the union has a law to this effect (look for unorganized militia in the index). The feds have the same law. Note the national guard is not a militia. As for the words "well regulated", in 18th century English this meant disciplined--not regulated in the post-new deal sense the word has taken on. The rest of the text probably mirrors our modern understanding.
And, lastly, the bazooka argument (this also applies to the howitzer argument ect. Those generally are explosive devices not covered by the text "arms." These argument are generally fallacious as being "slippery slope" and are unresponsive to say assault weapon bans.
If anyone needs cites, or wants some cites to the latest scholarly articles just pm me, or let me know on this form.