As Clinton and Obama vie for the Democratic Prize the likelihood that two factors the democrats will find uncomfortable may come into play in the decision. Superdelegates are one factor -they represent about 20% of the delegate total in a handful of influential party players. Here is a Superdelegate running total. With most still uncommitted, I think it's increasingly unlikely that we'll see these superdelegates make the difference. The issue is becoming controversial enough that most will stay uncommitted until a concensus position develops - perhaps as late as the convention but if Obama continues to rule the primary roost look for many superdelegates to shift to his camp. Clinton is far more vulnerable to claims of playing insider hardball than Obama, so ironically the superdelegate issue may wind up working to his advantage. He can claim a Clinton superdelegate lead is from party politicking where his superdelegate gains are legitimate.
I think a more important factor could be the inclusion of the results of the Florida and Michigan primaries. These both went to Clinton and would swing the delegate total even more strongly in her favor. In fact if Clinton takes New York and Pennsyvania the count should stay close right up to the convention.