Hi Shane,
We realize that many people need this feature, and development of SL 5 support is currently active. I'd be glad to tell you about the progress on this and give you a time estimate, but I just don't know. There's no exact information on this at the moment. So, I cannot promise anything as you probably understand.
Currently, as I wrote in my previous posts, there's a temporary solution - x86 browsers and TC 8.70. SL 5 support works there. At the present stage, this is a limitation, but you should be able to test it anyway. Some specific things may not work (such as accessing the WebBrowser control as Olga mentioned in this thread), but most areas should work already. So, present and potential customers can start developing SL 5 tests.