Only one IPVC MCU may be associated to a MeetingPlace system through the video integration. You can find out more information through the link below.
Administrator's Guide for Cisco MeetingPlace Video Integration Release 5.3:
http://www.cisco.com/en/US/products/sw/ps5664/ps5669/products_administration_guide_book09186a0080334949.html
As for redundant pairs, I am guessing you taling about the MCU. Currently this is a manual process where you would have a system in standby mode configured exactly as the live system and swap the network connection between the two. It is not the best scenario but hot-standby is not available currently with this solution. This should also be covered somewhat in the Administrator Guide above.
