I know this is a bit premature since we don't have any official rooted sightings yet, but I was talking to my sister last night, she is thinking of getting a Droid with her upgrade, and she doesn't care which one she gets (Either will work fine for her).
She suggested that she could get the Incredible, and then swap with me, which would work because I can leave it rooted and reflash it with the stock CM image for her, and then I'd have the DI.
I'm not sure if I want to do that though, because I've got my Droid to where I like it and it's benchmarking faster then stock Incredibles, (which makes me really itch with anticipation of overclocking the DI). I'm also not sure how long it'll take before we can get it rooted.
Are there plans to port CM and ROM Manager to the Incredible when it does get rooted? I am absolutely in love with ROM Manager, I've reflashed my phone and kernel sooooo many times in the last two weeks trying to find what works best with my specific phone, and I really like what has been done with CyanogenMod, I'd love to run it on a DI with a bekit 2.0GHz kernel