Apparently the mayor offended “dear leader Putin” by criticizing the standing government. Apparently the Moscow mayor serves at the pleasure of the president (it's in their constitution).
I've heard that Luzhkov is Putin's man, and that this may be the opening bell in the May, 2012 Presidential election race between Medvedev and Putin.
(The Russian Constitution allows the President no more than two terms in succession. This means that while Putin could not not run again in 2008, he can run again in 2012. The equivalent would be if our Constitution said that George Bush couldn't run again in 2008, but could run again in 2012.)
There has always been a question about whether Medvedev would step aside in 2012 and not oppose Putin's election in that year. This firing may be the first indication that the answer to that question is “Nyet”.
This is how KGB Incorporated pays back its friends, by stabbing them in the back. Just look at the Kremlin campaign now to unseat Moscow's slavish lapdog Lukashenko in Belarus. Both campaigns were carried out by a Gazprom owned TV station. This is the price of appeasement. Nazi Russians like Vlad Zhirinovsky are delighted by these events.
That does make sense, thanks for the clarification. Perhaps you are right, Medvedev intends to be his own man.
CC