What's interesting is that the Second Amendment does not appear to have been raised in the appeal and is nowhere mentioned (at least in my scanning of it) in the Supreme Court opinion: US v. Hayes, 129 S. Ct. 1079 (Supreme Court, 2009).
The issue, as described in the introductory paragraph to the opinion, is very narrow:
"...The definition of "misdemeanor crime of domestic violence," contained in § 921(a)(33)(A), is at issue in this case. Does that term cover a misdemeanor battery whenever the battered victim was in fact the offender's spouse (or other relation specified in § 921(a)(33)(A))? Or, to trigger the possession ban, must the predicate misdemeanor identify as an element of the crime a domestic relationship between aggressor and victim?..."
SCOTUS went on to remand the case to the Fourth Circuit for further proceedings.