What are you most concerned about as you embark on creating a curriculum unit?

Gus and I will be creating a curriculum on quadratic functions. While I've taught this topic many times, I have never taught it online. I am most concerned about the efficient online delivery of content, especially because the discussion forum, a virtual classroom tool I'm most familiar with, may be difficult to use heavily in a math class. I also want to make sure that I use online resources to the best of its capabilities, rather than being tethered to the teaching methods effective in a physical classroom. This project should be very interesting and challenging. I hope that we are able to develop an excellent curriculum that can be used.