The Most Important Functions of a Tablet Collaboration / Communication App

I am wondering if I may get some feedback on the most important functions of a tablet communication/collaboration app? We have just launched our NetConference app for iPad and it has more features than all of the other products combined. I am writing our promotional commercial for this product over the holidays and looking to outside groups to help me know what I should feature most in a commercial.

For example, of these features, which would you think is most useful?

8 People on Camera and VoIP

Shared Video on Demand to watch videos together

Shared Media on Demand to review Powerpoint, Word, PDF, Excel and Jpgs together

Multiperson Chat

Multiperson Whiteboard

All of your presentations stored in the cloud for instant access

or the Ability to host the conference from your iPad?

I really appreciate any feedback on this! When you have dreamed it all up and built the product you fall in love with your features.... and then you do not know what others find most valuable.