This term, the United States Supreme Court will hear arguments in the case of Gould v. United States. The question the case presents to the Court's Justices is an interesting one. Incidentally, newly minted Associate Justice Elena Kagan has recused herself from the case: she is the immediate past Solicitor General of the United States, and held that office while her staff was preparing for the Gould case. Here is how the Court's website articulates the question presented in the Gould case:
Did the United States Court of Appeals for the Fifth Circuit correctly hold, in direct conflict with the Second Circuit (but in accordance with several other circuits), that a mandatory minimum sentence provided by 18 U.S.C. § 924(c)(I)(A) applies to a count when another count already carries a greater mandatory minimum sentence?
Source: http://www.supremecourt.gov/qp/09-07073qp.pdf
That articulation of the issue may seem more mysterious than interesting, so here is the heart of the matter restated by James McHale and Alexander Malahoff, two law students at Cornell University's law school, who have written an exhaustive and recommended analysis of both Gould and its companion case, Abbott. The analysis, from which the excerpt below is taken, is available on Cornell Law School's estimable website:
"18 U.S.C. § 924(c)(1)(A) requires a 5-year minimum sentence for possessing a firearm in furtherance of a drug-trafficking crime - '[e]xcept to the extent that a greater minimum sentence is otherwise provided by . . . any other provision of law."
Did the U.S. Court of Appeals for the Fifth Circuit correctly hold, despite this 'except' clause, that a defendant is subject to the 5-year minimum sentence for the firearm possession even though another provision of law requires a greater minimum sentence for another count of conviction?"
In a nutshell, Mr. Gould committed a drug crime, the minimum sentence for which exceeded the five years called for under the federal statute under review, 18 U.S.C. § 924(c)(1)(A). What Mr. Gould is arguing is that, because his conviction for the underlying crime necessarily resulted in a prison term in excess of five years, he should be exempted from the additional punishment of five years called for under the statute under review- which runs consecutive to the prison term for the underlying crime.
The larger issue in Gould, and also Abbott, is what scope the Supreme Court will give to the 'except' clause in the federal statute. If, for example, the Court rules that the 'except' clause's reference to "any other provision of law" refers only to other provisions of law covering the same offense, then many convicted defendants will face longer prison terms than would be the case, for example, if the firearm charge pursuant to the statute were merged into the underlying and predominant charge a defendant is charged with.
Conversely, if the Court rules that the 'except' clause's reference to "any other provision of law" applies to . . . any other provision of law (that is to say, without regard to the substance of the charge), then the federal statute, enacted to express society's view of violent drug crime, will be devitalized.

