I can't recall a case getting this much coverage at the cert. stage. Or at the merits briefing state, either. Usually a Supreme Court case is ignored until the Court rules (and often even after that: in a Term the Court takes about 80 cases, but upwards of 70 are not very sexy). But...
Michigan Atty General Mike Cox weights in with textual argument.
Here's a pretty good general article on the case.
And here's the Brady Campaign press release, calling the Circuit ruling "judicial activism at its worst." Further proof that, in many cases, "judicial activism" amounts to "striking down a law I wanted upheld."
The Harvard Law Bulletin reports that Prof. Mark Tushnet thinks DC may win, while Prof. Larry Tribe thinks the plaintiffs will. It quotes Prof. Tribe, who came over to the individual rights view: “My conclusion came as something of a surprise to me, and an unwelcome surprise,” Tribe said in a recent New York Times interview. “I have always supported as a matter of policy very comprehensive gun control.”"
And we shouldn't neglect academia. Here's Nelson Lund's latest, refuting the argument that since the amendment relates to the militia, and handguns are supposedly not militia weapons, they can be banned.