• Here's some info that seems to have helped some other 10.8 presenters:
  • http://support.blackboardcollaborate.com/ics/support/KBAnswer.asp?questionID=2607&hitOffset=81+80+54+53+14+13
• Also, from a user:

I'm so sorry you're having java issues on your MacBookPro! The problem you are describing is an Apple problem because they are no longer updating the Java with Software Update and the new java version doesn't work on Macs. I knew that was an issue so I have not updated java and I have no problems accessing the sessions on my iMac and MacBookPro. I can also access them on my iPad using the Blackboard Collaborate app and can see and hear everything except for web tours. 

"There is a difference between running applets and having Java installed. Apple -installed- a new version of Java. Apple -uninstalled- the automatic running of web-based applets using that Java."

Do you have a backup copy of Java in your TimeMachine? You might be able to go back to that version. I'm using Java SE 6 version 1.6.0_35-b10-428. This is an explanation offered by AppleInsider about the java updates.
http://appleinsider.com/articles/12/10/16/software-update-removes-apple-provided-java-applet-plug-in

If you are brave and want to try using your Terminal commands you can fix it following this advice shared on my Mac Users Group.
http://support.apple.com/kb/HT5559

You can also check with the Collaborate user group at http://www.wecollaborate.com.