A Clinton-Obama ticket?

What surprised me the most is that Clinton should suggest that she might be on the top of the ticket although she is running slightly behind him in the primaries. Such a gesture is usually made by the front-runner to a weaker candidate in the hope of unifying the party, at last. The consequence of this smart political tactic is that it places the Obama campaign in a bit of a dilemna : 

• accept the offer and give up its aim of changing politics
  
• refuse the offer and appear as over-ambitious and be seen as the divider of the party that is need of unity. 
  

 The question is, at this point, hasn't there been too much bad blood between the candidates? 

The other incongruity of this proposal is that Clinton considers Obama not to be ready to assume the responsabilities of commander in chief but would accept him to be "one heart beat away" from being President : remember that the VP is meant to replace the President should anything go wrong.  

I wonder : is it politically wise for her to make such offer (positing herself as the real front-runner and making a move in favor of reconciliation), or does it simply look incredibly brash, disconnected from reality and condescending ?