I think Vitali NEEDS David Haye for his legacy. Don King ruined his bids to fight Valuev and Ruiz and without those fellow titlists on his resume, it truly drops his stock.
A win over Haye, especially at 41 or 42 y/o would greatly improve his resume and bump him a spot on the ATG list, perhaps even into the top 10 on most writers/fans lists.
I personally think he's got 2 more big fights in him. I'd like to see him fight Haye in May, then come back in Sept or October and beat either Fury or Sitverne.