Just wondering, but why would you also need an audio out when you can charge and then just plug your audio cable right into the 3.5mm jack on top of the Incredible?
EDIT: Ok, I just realized why. You want to have the ability to just plug in ONE cable instead of two. Well, unfortunately I don't have an answer to that just yet as I'm also waiting for my Incredible to ship. But I'll get right on looking for a solution for ya