The IPO curves in 2.57 are now called F-Curves and are basically split over the dopesheet / N(on) L(inear) A(ction) editor and graph editor. I have not personally used it as yet but as I understand it, particular actions such as smiling / blinking for example, can be defined using the NLA and graph editors and combined with further predfined actions using the Dopesheet. This means that a particular action can be used over several instances in a particular animation without having to keyframe it again.

Take a look at some of the tutorials at Blendercookie.com (rigging and animation) or blenderguru.com (how to animate a muzzle flash) to get an idea of how they work together.

 Sorry I can't be of more help.