Galaxy 17 was moved to 123 as a backup in case something happened during launch or testing of Galaxy 18. G10R will be replaced with G18 once in orbit testing is done. 123 West is a important location because of its use for
C band feeds to cable headends. Those content providers uplinking to 123 west pay good money for that location and they expect 100% uptime with no loss of signal. Everyone, C and Ku users should see improved signal strength and quality once G18 becomes operational. I would expect them to finish testing in the next week or so and to start moving feeds to G18 soon. Galaxy 17 will be moved back to 91 west to replace G11 since it has the same fuel and control problems that G10R has due to poor design of the ION thrusters onboard.