Stock prices are influenced by so many factors. Sony stock is up over 100% year to date, and the entire market is hitting all time highs. There could be a short squeeze, it could be due to broader economic data, some technical indicator, or a hedge fund upping their stake in Sony:
http://dealbook.nytimes.com/2013/05/14/hedge-fund-manager-da...
I really doubt it has much to do with a Microsoft presentation.