People who know about treaties, please let me know your thoughts, but I don't see this language standing up in court.
The Congress approved the Geneva Conventions which are a treaty. As such, the remedies are either specified to be handled by an international tribunal or by each signatories' own legal system.
As such, I don't see how Congress can amend the agreement to read that the President can interpret it. Either it was written into the Conventions and so by altering it we nullify our participation, or it's an act of congress and the courts have the right to ensure the executive's adherence.
In our system, judges get to evaluate the executive's execution of the congressional legislation, and I imagine 'activist' judges will definitely assert their right over such manners.
As such, the clause 'the president can "interpret the meaning and application" of the Conventions can not stand.
Note to commenters after the fold:
**Saying that laws don't exist anymore because of the Chief Decider is foolish and self-defeating - we really need to be aware of our legal recourses because as has been shown time and again under this administration and legislature - the courts are our last line of defense. The only reason this legislation is being considered is because the court in Hamdan already said that we were meeting our obligations of Habeas Corpus and the Geneva Conventions. Exaggerating the admittedly bad situation we're in is not in the least bit productive.**