as much as I would like to see it live, I think if it comes it will be sort of like what happened with Evita, you had a London production and it took forever to reach Broadway and when it did, it sort of did so out of the blue.
As for how long it will run, I think it really depends on where it plays and how it is marketed. If it can get a tourist following it will have a good run, but these days it is not easy to predict what will be a sure hit or not.
Also, I believe they probably will use the Aussie design (Unless they do a 3rd total re-design) and I dont know if there is any president regarding a show being on DVD BEFORE it comes to stage, and how that might help or hinder the production. Usually we have it the other way around.
http://www.flickr.com/photos/27199361@N08/ Phantom at the Royal Empire Theatre