There is a big reason that I haven't seen anyone talk about why I think we haven't seen a mass migration, winter-goose like, to either Obama (in hopes of settling matters), or to Clinton (because they may think she is more electable).  Consider the question from their standpoint, in the glowing light of their erstwhile interest in minimizing their own political risks.  Bottom line: why put your neck out if you don't have to?

Either one of two situations is going to occur: one of the candidates will prevail, prior to the last primary battle, or Obama and Clinton will both make it to the end, and the SDs will have to weigh in.  Most every SD is hoping for the former situation.  If Clinton dies on the vine on March 6th in either Indiana or North Carolina, or runs into trouble in any of the following matchups, her already very long chances of getting the nod will evaporate, and she'll throw in the towel.  If on the other hand, Obama finds himself in troubled waters, either because of his Reverend Wright troubles, or because Clinton's accumulation of momentum over the last week takes on serious proportions, and causes an upset on the 6th, then he may find (though at this moment it seems near impossible) he cannot make it to the end either.  Either way, if this were to occur, the Super Delegates work of choosing the candidate will be done for them.  No mess. no fuss.

The last thing any superdelegate wants is to commit to the candidate of their choosing, only to have them lose it before the convention.  Facing home state or local voters who they may have departed from, or explaining their choice when the other side prevails is a task they'd all like to avoid.  Thus, I think we're going to see most of the Super Delegates sitting on the sidelines until circumstances decide the nominee for them.