Research in Motion (RIMM) +6.7% premarket after getting another upgrade from Jefferies' Peter Misek, this time to Buy with price target of $19.50 (from $13). The new BB10 OS will enable corporate email on iOS and Android devices, he says - something the market is unaware of. In the most bullish scenario, he puts a $56 price target on the stock vs. a previous $43.