I have a logo on the Attend page, but can I customize the interface more than that? I would like to have the company name instead of "cisco meetingplace express".
Also, How do I change the voice prompts when people call into meetingplace express?
Cisco does not document rebranding the product. It should still have the Cisco MeetingPlace Express branding. You can deffinately customize the voice prompts.
Voice Prompt Reference (English) for Cisco Unified MeetingPlace Express
The "Cisco meetingPlace Express" is actually an image. What you can do is create your own image and than upload it to MPE via SCP. I am going to assume you know how to navigate through the linux cli. You need to be logged in as root. The file name is logoMPExpress.jpg and is located in the following directory: /opt/cisco/meetingplace_express/web/versions/126.96.36.199/bases/main/webapps/ROOT/public/common/images/
The file is being used by several of the CSSs so it would easier to name your image as the same. Hope this helps.