25. Stephen Elop, President and CEO, Nokia - Most Powerful People in Wireless

25. Stephen Elop, President and CEO, NokiaWhat makes him powerful: Stephen Elop--who ran Microsoft's $19 billion business division and was responsible for the company's Office product suite--is the first non-Finn to run Nokia (NYSE:NOK), and has been charged with turning the ship around.

Elop replaced Olli-Pekka Kallasvuo, who had been at the helm of Nokia since 2006. Kallasvuo was criticized for moving too slowly in the smartphone market, and for failing to deliver hit, high-end smartphones to match Apple's (NASDAQ:AAPL) iPhone, devices running Google's Android platform and others.

It is too soon to know whether Elop will be able to right this ship, but he's clearly in the game. "Nokia has been characterized as an organization where it is too hard to get things done," Elop said during the company's third-quarter earnings conference call. "More than anything else, the changing market dynamics demand that we must improve our ability to aggressively lead through changes in our environment."

Elop, who moved his family from the United States to Finland, has already made a few bold moves. He cut 1,800 jobs as part of a reorganization of Nokia's Symbian smartphone production that combines the development of its Symbian^3 and Symbian^4 OS.

In addition, Nokia will embrace the Qt cross-platform development environment as its sole application creation framework. This means that moving forward, developers who build apps in Qt will be able to deploy their software across devices running both the Symbian and MeeGo operating systems.

There is no shortage of pundits telling Elop what to do, but to become a truly powerful figure in the wireless market, he will have to restore luster to Nokia's high-end smartphone business and also find a way to crack the U.S. market--goals that Kallasvuo missed. --Phil

25. Stephen Elop, President and CEO, Nokia - Most Powerful People in Wireless