The “superdelegates” are those delegates to the Democratic National Party that are not selected through the primary or caucus process. They get their position by being elected party members or members of the party establishment. Near as I can figure, the Indiana based superdelegates are as follows:

Sen. Evan Bayh (IN)
DNC Joe Andrew (IN) – Former DNC national chairman
DNC Dan Parker – Indiana state Democratic Party chair
DNC Phoebe Crane – DNC member out of Whitestown, IN
DNC Bob Pastrick – DNC member and (I believe) former East Chicago mayor
(These folks have already apparently endorsed Hillary Clinton)

Rep. Peter Visclosky (IN-01)
Rep. Joe Donnelly (IN-02)
Rep. Brad Ellsworth (IN-08)
Rep. Baron Hill (IN-09)
Cordelia Lewis Burks – Indiana state Democratic Party vice-chair
Connie Thurman – DNC member out of Marion County
(These folks have apparently not endorsed anyone yet.)

The “committed” superdelegates are not under a formal obligation to stick with their commitments, though obviously it would probably be at least awkward to back out on whatever deal they made with the candidate to whom they pledged support. In recent history, these superdelegates have just been a formality – their votes haven’t made any more difference than Indiana’s Presidential primary has made. At the time the Clinton endorsements came out, there probably wasn’t any reason to think that this year would be much different. But, now things are shaping up to be interesting. I’d hope even the committed delegates would consider keeping their minds open in the event Indiana should go big for a fellow midwesterner as opposed to the Senator from New York. (Even if we do share a time zone with the former and not the latter. — You probably didn’t think I could work time into this.)