Kevin Johnson, Juniper Networks
Juniper Networks had a tough 2012 as the company posted lackluster earnings and saw slow adoption of QFabric, its big data center bet. The company was also struck with a number of notable executive departures as well as layoffs and restructuring. Now Johnson is facing pressure to not only step up Juniper's data center play but also ramp up the company's security offerings, which have lagged behind the competition. Meanwhile, Juniper's stock price has fallen from $22 in February to $15.80 today, and the company said it expects continued weakness in the enterprise market for the current quarter.