What next for Mr Putin?
Perhaps I should start with a statement of the blindingly obvious: Russia is not Egypt.
Yes, there were thousands of anti-government protesters out on the streets of the capital this week. And yes, the security forces responded with great brutality. And yes again, online social networks played an important role in galvanising the protests and giving a voice to the protesters.
But no, an autocrat is not about to be toppled. And no, Vladimir Putin is not Hosni Mubarak. So I suspect any references to a "Russian spring" (in December, for goodness sake?) should be taken with a very large pinch of salt.
Let's rewind a few days. Last weekend, Russian voters went to the polls to choose a new parliament. This is not an event that normally excites much interest, because there is rarely any doubt about who is likely to win.
But this time was different. It was the first test of public opinion since Vladimir Putin (currently prime minister) and Dmitri Medvedev (currently president) announced that they intend to repeat their little trick of four years ago and swap jobs. (It's not an exact repeat, in fact, because four years ago, Mr Medvedev was a mere deputy prime minister. But the principle remains the same.)
It seems that Russian voters - or at least some of them - object to being treated as irrelevant by-standers at election time. Last month, there was an embarrassing episode when Mr Putin was booed at a martial arts contest where he tried to make a speech. These things shouldn't happen in what the Russians call their "managed democracy".
Then, in the run-up to last weekend's parliamentary elections, opposition groups started a campaign to persuade voters to vote for any party except Mr Putin's United Russia.
When the results were declared, they showed a substantial drop in support for United Russia. What's more, according to independent election monitoring groups and foreign observers, the party would have done far, far worse had there not been widespread vote-rigging and fraud.
That's why the protesters took to the streets. It's also why they intend to do the same thing this weekend, after an online campaign that is reported to have gained tens of thousands of supporters.
What does it all mean? Well, it's easier to suggest what it doesn't mean, because no Russian analyst to whom I have spoken this week believes that Mr Putin will not be re-elected as president next March. (Apologies for the double negatives: what I mean is that every Russian analyst to whom I have spoken believes that Mr Putin will be re-elected next March.)
Millions of Russians remember the chaotic days of the Yeltsin era, and the financial melt-down which left the vast majority struggling to make ends meet, while a handful of oligarchs snapped up State enterprises and turned themselves overnight into billionaires. There is very little appetite to return to that.
Vladimir Putin has meticulously cultivated an image as a strong leader (remember those pictures of him bare-chested?) while benefiting politically from high oil and gas prices, which have sent billions of dollars cascading into the Kremlin exchequer. It all goes down well in a country with a long tradition of strong leaders.
But something did shift this week. After too many years of cronyism, corruption and inefficiency, young, educated Russians seem to have decided they want something better. The chant of the protesters was "Russia without Putin".
Did they take their cue from the Arab spring protesters in Tunisia and Egypt? Not consciously, perhaps, but 2011 has become the year of street protests - all the way from the capitals of the Arab world to the Occupy movements of New York, London and many other major cities.
It's interesting, isn't it, how in an increasingly virtual, digitised world, lived more and more on line and on screen, the most potent form of political action once again is the mass protest on the streets and in the squares of the world's major cities.
For now, Vladimir Putin seems determined to blame Washington for his troubles. Hillary Clinton has been rude about the conduct of the elections; and in return, Mr Putin has accused the US of spending hundreds of millions of dollars to influence Russian politics.
So far, so predictable. Far less predictable is how the anti-Putin protesters will respond when the security forces try to put an end to their demonstrations.
On your list of things to watch out for in the coming year - the economy, the euro, the Olympics and the US presidential election - you can now add one more item: Russia.