Cisco choose not to enable the video functionality of the Breeze UI within MeetingPlace Express. You would need to use an onnet video-capable end point such as a 7985. MPE only provides voice activated video switching of the conference. You have no floor controls available.
Alternatively, you can look at WebEx, Cisco Unified Video Conferencing (CUVC), or MeetingPlace 7. Each has a slightly different story and this entire product line is going to significant transition right now.