The key is:
"The court has held that most of the rest of the Bill of Rights applies to state and local laws. But Feldman (lawyer for the Chicago gun banners) said the Second Amendment should be treated differently because guns are different. 'Firearms are designed to injure and kill,' he said."
You can almost hear the sighs at that chestnut, and they may have come from some of our Supreme Court foes as well as the five who gave us the Heller relief.
A decision for McDonald will severely limit application of (and perhaps nullify?) the 1873 Slaughter House Cases which permit states and localities to pick and choose among many federal Constitutional protections they must grant their citizens. The Left is no fan of the Slaughter House construction and thinks its abolition might smooth the way for some of its agenda.
A pro-McDonald resolution will still leave us a thousand battles to fight in the cities and states where the spirit of Heller is detested, where bureaucrats and elected officials despair at the notion that a person's right to defend himself is both individual and inalienable. But it will be an easier fight with High Court's basic interpretation of Amendment Two on our side, with the death of the notion that guns are only for those who at the command of the current government administration.
Decision expected in June.
EDIT, Mar. 3: A number of writers are suggesting that the Slaughter House Cases were not successfully attacked in the orals yesterday. Their interpretation is that the justices are unwilling to reopen "incorporation" arguments under the Constitution's privileges and immunities clause since the application of the Second Amendment, as defined by Heller, can be accomplished by application of the due process clause.