It was reported in Election Central that a pledged delegated in Maryland who was elected for Hillary has "defected" and will now vote for Obama instead.

Not long after reading that, I noticed that CNN lists Edwards as having 19 pledged delegates.  It got me wondering as to what (if anything in particular) would or should guide their decision-making from here on out.

Will they vote for Edwards at the convention despite the fact he's out of the running?  Or have they become, in effect, a new mini-pool of super delegates who are free to throw their weight behind either of the two remaining candidates?  And if it's the latter, are they expected to vote for whoever was runner up in the districts they represent, or are they just supposed to go with whoever they happen to feel is the stronger candidate?