Monte Cristo games have just issued a statement saying that the MMO element of Cities XL is going to be shut down:
"Three months after the launch we have to admit that the subscription rate is lower than what we expected and therefore the Planet Offer is not sustainable. Not enough players decided to subscribe. Therefore, it is with deep regret that we decided to put an end to the Planet Offer as of March 8th 2010. It will no longer be possible to subscribe to the game starting Monday February 1st 2010."
The single-player game will
continue to be supported with add-ons and patches be given a sequel, Cities XL 2011. There's a detailed FAQ on the situation here.
Dave Tosser says: This should not be seen as a failure, because adding MMO aspects on to all games, whether or not it's a good idea, is the responsibility of all profit-minded companies. Without a subscription model your game is just another backward looking product. And you know what they say: "profit makes even the fattest men even fatter."