It looks that the future updates to FaceTime may enable multiparty conference calls with 3 or more people. This would work extremely well on the iPad's large screen, and would give Apple the edge over competing business-centric tablets (like BlackBerry's Playbook) for corporate use. Skype also recently updated their Windows app to support group chat for up to 5 people, so matching this would be the logical next step for Apple.
A user has found following key in FaceTime's code: <key>AllowsMultipleConnections</key><false/>
Setting the value to "true" may enable this hidden feature.
The file is located at: /System/Library/PrivateFrameworks/IMCore.framework/imagent.app/PlugIns/FaceTime.imservice/ServiceProperties.plist