I thought I already commented here about Putin's reappearance, but apparently not.
Anyway...
http://edition.cnn.com/2015/03/16/world/russia-putin/index.htmlHe makes jokes about this but it is undeniable that his disappearance has revealed a massive weakness in Russian society and politics. Any appearance of weakness from Putin was so devastating that they had to fabricate stories about him meeting up people and publish them in news (which they accidentally did before the meetings happened...) and the whole world was watching them shake in their boots. This means that the next time something like this happens (when he gets flu or anything more severe) we are likely to see his rule start to crack just like it did now.
And the danger isn't just that someone tries to usurp him, the bigger problem is something rather more surprising. Russia seemed to be paralyzed without Putin. He has turned himself into the one supreme ruler and without him even the daily proceedings are in trouble.
So on one hand he has proven proven the strength of his grip as Russia can't survive without him, on the other hand he has revealed the weakness of Russia as it can't survive without him. (Or at least the current regime can't.)
Or maybe Nemetsov was just faking his death and used these 10 days to cut off Putin's face and plant it on himself.
Or maybe Putin was replaced by five squirrels in a human-suit.