I'm postulating here, but I believe superdelegates are state party officials that are not beholden to anyone based on the primary results, which elect the slate of regular delegates. As with the electoral college, even the elected delegates are not
required to vote for their nominee, but it would be bad form, at least in the early nomination rounds.
The primaries are strictly party functions, they can make up their own rules, hence the GOP has gone primarily with winner-take-all results while the Dems are apportioning them based on percentage results, and on almost a precinct by precinct basis. A candidate could win the popular vote in a state and still get fewer delegates, which I think was the result in Nevada.
This guarantees that the Democratic contest will likely go to the very end before determining whether our next president will be the first female or minority POTUS.
The superdelegate setup has been there all along, it is not a result of the MI/FL issue. By the way, even before those primaries, they were saying that those delegates would get recognized at the convention in order to avoid antagonizing the populations in those great states.
Well, a little search on the notorious Wikipedia on Superdelegates turned up the following (I wasn't too far off!)...
Superdelegates are delegates to a presidential nominating convention in the United States who are not bound by the decisions of party primaries or caucuses. Superdelegates are elected officeholders and party officials. They are sometimes referred to as "unpledged delegates", but some unpledged delegates are not superdelegates.
Superdelegates were first appointed in the 1970s, after control of the nomination process in the Democratic Party effectively moved out of the hands of party officials into the primary and caucus process. The aim was to grant some say in the process to people who had been playing roles in the party before the election year.
The Republican Party has 123 similarly automatically appointed delegates, members of the Republican National Committee. Including these appointees, the Republican Party has 463 unpledged delegates out of a total of 2,380 delegates.