A serious question: are the benefits really worth it? How much overhead would it be to just include the library code directly into the contracts instead (so that the whole thing can be verified as a single black box)?
I'd like to point out that the idea of including the library code within the contract is untennable at a certain level as contracts currently have an upper limit on size which is determined by the block gas limit. It also doesn't make it any safer because it's still functionally the same as executing external code because it's the same code being executed.