I don't see any way that Hillary Clinton can overcome Barack Obama's delegate lead, and apparently, others are starting to recognize that fact as well: http://www.timesonline.co.uk/tol/comment/columnists/gerard_baker/article3884579.ece. He cleaned her clock in North Carolina, and she barely beat him in Indiana. The only possible way she could win now would be to get the Michigan and Florida primary votes to count--she won't win that battle--and then to convince the superdelegates to come down on her side, which is increasingly unlikely.
The long and the short of it? Hillary Clinton's 2008 Presidential campaign is toast.