I followed the directions from here: http://www.sitefinity.com/support/kb/article/sitefinity-3-x/how-to-wrap-a-generic-content-control-in-3-6-sp1.aspx
One extra setup that wasn't mention in the article was to add the control to the web.config so that it seen in Sitefinity.
Ok so, here's the problem...
Now when I drop the control on to a page, I can "edit" the control and I see the "Generic Content Control" WYSIWYG editor. Good. This works as expected. However, after I enter content and save it.. I see this error on the content place holder section were the control was added to in the design mode... "This control will not display properly in design mode".