"A similar problem has plagued Medvedev throughout his presidency. Whenever his limousine approached the Kremlin, the security guards would announce: "The president is about to arrive!" But when it was Prime Minister Vladimir Putin in the limousine, they would say: "Nastoyashtchiy yedet" -- "Now the real one is coming."" http://www.spiegel.de/international...s-betrayal-of-russian-democracy-a-789767.html
I would suggest that the only way for Putin to not run for President again would be if he was either medically incapacitated or dead, even the Russian constitution limiting Presidents to a two term maximum would likely be amended whilst he was Prime Minister. If he decides not to run again in 2012 he merely continues to run the government via remote control. Had he died early enough in his second term as Prime Minister it would likely improve his reputation since domestically Medvedev would be left holding the bag during the 2008 recession and 2015-16 downturn, and internationally by avoiding Crimea, Syria, and the US Presidential elections.So, what if V.V. Putin decided that he will not run for third term in 2012?
There are several possibilities. Least realistic is that he acted like more or less genuine democratic leader, did not kill off credible opposition and retired after his term, perhaps as the founder of a political party. To be fair that would probably mean a resurgence of olygarhic-backed political figures, but could pull through to something resembling a modern state as well.
Second is that he does not run for third term but stays behind the throne. Then nothing changes really. Medvedev invaded Georgia after all. There may be a difference in internal Russian political scene, but not for the outdide world I think. Also he may be undermined eventually and forced out. Maybe even in 2014 or something.
Third is he suffered a health problem or an accident and removed from politics. In that case I don't think Medvedev would last more then one term. Putins former clique would try to remain in power, but how successfully depends on their actual competence and ability to cooperate. That would likely butterfly off Ukraine invilvement and Syria as well.
If he stays PM and not going to run for president again, he probably remains the main figure anyway. In that scenario there is still no real opposition and Medvedev probably wins in 2012. There would not be an extension of presidential term from 4 to 6 years, so someone else would be promoted to presidency in 2016. There could really be anyone. I think Shoygu or Sobyanin may be good candidates if Putin manages to hammer them through.I was actually thinking more about "more or LESS genuine democratic leader" scenario, where he decides in 2008 to become the PM to "help" Medvedev for a single term.
If he stays PM and not going to run for president again, he probably remains the main figure anyway. In that scenario there is still no real opposition and Medvedev probably wins in 2012. There would not be an extension of presidential term from 4 to 6 years, so someone else would be promoted to presidency in 2016. There could really be anyone. I think Shoygu or Sobyanin may be good candidates if Putin manages to hammer them through.
If crackdown on opposition is relaxed, we may even have Navalny as a rival candidate, though I am not sure if he had any support outside Moscow and St.Petersburg. Though his victory would be a Trump-like shock...
Ivanov, perhaps? It really depends how well Putin would continue to control the political situation. In 2012 he managed to pacify protesters with his election promises and the level of fraud needed to elect him was much lower anyway then for say Medvedev if he ran (mostly to make the victory look more solid then for victory itself). Without it the situation in Russia may be less stable. There is a possibility that he had to agree with some other candidate.Yes, that interested me. Any other names?