If I were designing an Architecture and Engineering class to be delivered through Elluminate, I would definitely have to plan many different types of activities. First off, whenever I introduce a new topic, I am usually using some sort of CAD program to explain the skill. My Elluminate session would have to have video capabilities as the whiteboard would not be suffice for the lesson.
I also would have to take into account the need to practice the skills learned in the class session. In a face-to-face classroom setting, I am able to walk around the room and observe a student's progress. If I were using Elluminate, I would do the same by setting up individual break-out rooms and enter each room and have a few minutes of one-on-one instruction with the students. Break out room also could be used as we do in NTI. As a transfer-in, I could have students collaborate in their groups to complete some type of review assignment to reinforce the previous content.
These are a few ideas to get the creativity flowing. I'm sure as I began to use the software and it's capabilities, I would come up with different types of strategies for teaching the content.