Well adobe has their Connect [1] application. It runs in flash and can share a desktop [2], so I know something exists. Although I think people are changing over to Java for screen sharing these days since it's installed in most places already.
[1] http://www.adobe.com/products/adobeconnect.html [2] https://community.apan.org/cfs-file.ashx/__key/communityserver-blogs-components-weblogfiles/00-00-00-40-40/5672.Adobe-Connect-room.png -Mark
