Last Call: Mike Tyson and Microsoft By: CNBC.com News June 18, 2012 at 23:22 PM EDT Microsoft unveils a tablet it hopes can rival the iPad; Oracle announces earnings early; a key exec departs JC Penny and Carl Icahn gets an ally on the Chesapeake board. Read More >> Related Stocks: Chesapeake Energy Citigroup ConAgra Foods Hewlett-Packard J C Penney Company Inc Microsoft Target Corp