Not yet.  Currently pools must update so masternodes get paid. This is already underway.

Furthermore, the blocks that the network thinks should be rejected are currently being recorded in the logs. Once the logs check out (i.e. there are no bugs), enforcement will be switched on remotely by Evan. This is stage two of the launch.

The good thing is that you DON'T need to update again to be ready for the enforcement and masternode payments will not need to be stopped for any reason.