Deputy Prime Minister Dmitry Medvedev, who chairs the board of Gazprom, is widely seen as the front-runner to succeed Putin, followed by Defense Minister Sergei Ivanov. Other potential Putin successors reportedly include Russian Railways President Vladimir Yakunin, Kremlin chief of staff Sergei Sobyanin, and St. Petersburg Governor Valentina Matvienko. [emphasis added]
The article above is not actually about the presidential candidates. It is about the conspiracy theory that Anna Politovskaya was a victim of a power struggle behind the scenes of the Kremlin. I just took note of the presidential 'frontrunners'. All I can say is that the idea of the chairman of the board of Gazprom or the current defense minister being President of the Russian Federation produces much indigestion.