Assuring that is the main goal of presenting TBB as a dynamical library.
(Added 2012-12-04) I'm agnostic about these multiple instances (really multiple copies in the working program, or just multiple copies in the file system with only one of them actually linked in, or a simple mistake in the question itself?), because I expect TBB to behave no different than the runtime library (having more than one new/delete pool tends to be a show stopper before you get to worry about more than one thread pool).