for another module I plan to add an additional array key in hook_libraries_info().
#1781794: Registration of additional PSR-0 folders in modules and sites/all/libraries
I would find it very attractive if I could put closures (anonymous functions) in there.
Unfortunately, I found that php cannot serialize closures.
So, the question: Do you ever plan to serialize the result from libraries_get_info(), e.g. to cache it between requests? Because then the closure is out..