Josh Burton recently released his Morpheus Rig as version 1.0. He notes that it is not everything that he wanted, but there has been a ton of things added and fixed from the beta releases to make this an amazing rig to use! Download the rig, and check out the docs!
Josh started the Morpheus Project back in May of 2010 just for kicks and some specific goals in mind… To create a flexible bipedal character for animation tests and even projects including modifiable body and facial proportions and features; To develop more solid rigging muscles to add to his hireable toolset; Write some rigging tools using python to learn the language and speed up workflow; Using animator friendly principles from Jason Schleifer as well as ideas displayed in others rigs.
Play with the idea of a free baseline rig and a more advanced option set rig setup that I might charge something for to help support character making.