Is it complacency among most Russians these days that keeps Putin's group in power or the same old rule-with-an-iron-fist tactics? I think it's complacency. But I think things could change. just not everywhere in Russia at once. I think the Russia's biggest problem is that it's just too darn big.
Its the fact that the 6 years of his reign the country is growing, government workers are paid (including back wages), the unemployment rate is 7.9% (lower then most of europe: Germany 12.5%, France 11%, Poland 19%), foreign factories are flooding into the country, the Chechens are down to a few large attacks a year (the last was a total failure where they lost 5 men for every Russian killed), taxes are low (our are absolutely communist in comparison). Other then that, must be their lack of desire to return to the "freedom" of Yeltsin when they were economically raped every day while the Yeltsin intelligencia told them how stupid they were every day.
But you use your own judgement as to why.