The Strategic Rocket Forces are removing some of the UR-100NUTTH/SS-19 missiles from silos at the Kozelsk division to make room for future deployment of silo-based RS-24 Yars missiles. Deployment of silo-based RS-24 missiles in Kozelsk was expected for some time - it was mentioned in 2008 and confirmed in 2011.
In the last START data exchange in 2009 Russia reported having 29 deployed SS-19 missiles in Kozelsk. There were the total of 50 silos at that point. According to the news story linked above, 20 missiles of this type have not been removed yet. Whether they will remain in service during the RS-24 deployment is not quite clear.
Also, it is not clear if the UR-100NUTTH missile in Tatishchevo are being removed. The Rocket Forces said that the division in Tatishchevo will complete "re-armament" by the end of 2012. A literal reading of this seems would imply that UR-100NUTTH (there were 40 of them in 2009) will be removed, but that does not seem to be the case - my colleagues tell me that UR-100NUTTH are still deployed there. Also, the Rocket Forces said that some of the UR-100NUTTH removed from Kozelsk might be deployed elsewhere. Tatishchevo seems to be the only option.
Among other things, this means that my estimate of the number of deployed UR-100NUTTH based on the New START data is quite a bit off - I assumed that Russia had 35 missiles of this type in March 2012. In fact, this number could be as high as 69 - 29 in Kozelsk and 40 in Tatishchevo. To complicate the New START data-based estimates, some of the missiles in Kozelsk were probably in silos with their warheads removed, so while the missiles were counted as operationally deployed, the number of warheads associated with them was zero.