Hey, the folks at the Center for Media and Democracy, a nonpartisan group, does some of the best investigative research around:
Wondering what and who superdelegates are? The Superdelegate Transparency Project is the central gathering place for compiling primary and caucus results–Congressional district by Congressional district. It is housed in Congresspedia, a joint project of the Center for Media and Democracy and the Sunlight Foundation. Given the close nature of this year's Democratic primary, it is especially important that the role of the superdelegates should public knowledge, and the STP is using the power of crowdsourcing to make that happen.
The project features a state-by-state map of the United States, with lists of the superdelegates for each state, who they're supporting, and the popular vote totals and delegate counts for each congressional district. There are also biographical profiles and contact information for many of the superdelegates, and whether s/he has received campaign funding from a political action committee linked with Clinton or Obama.
Disclosure: I'm on the board of Sunlight, because they do the big stuff like this.