I'll agree that it is a bit disappointing, but look at it this way: it isn't watered down, and a 6-3 or 7-2 decision would have been. This is also a clear majority opinion, not merely a plurality one.
The majority opinion also all but gave us incorporation on a silver platter, by mentioning that the post-Civil War Congresses certainly knew the meaning of the 2nd...including the same Congress that passed the 14th Amendment. Say hello to a successful challenge to Chicago's ban, courtesy of Justice Scalia.
After thinking about these facts, we should all be ecstatic.