Word around the campifire is that Yahoo has been looking to buy Tumblr for $1.1 billion, but that that Tumblr thought that was not enough based on their $800 million valuation. The deal is set to be finalized by Yahoo’s board tomorrow, however, Tumblr may be getting cold feet.  Executives at Tumblr now feel this offer may be too low.  Microsoft and Facebook have both expressed interest in buying tumblr.  Generally when large acquisitions are serious “lock-up” deals are put in place to prevent bidding wars from other companies.  However, Mayer will need to act quickly once her board approves...