Tegan Summer Productions tried to make the Marilyn Monroe musical at Paris work, and there may be some good material there, but a 90 minute fast forward through the life of Marilyn on the strip wasn't the place to spend the money.
I'd think something like Moulin Rouge would do well. I was also in the apparent minority that thought Spiderman could actually work as a LV sit down.. there is Family Vacation money being left on the table in Vegas...I personally don't understand the draw of bringing families for a Vegas get-a-way, but since it seems to be continuing to happen, why not offer entertainment that would hold the kids interest a bit more than some of the Cirque shows.. regardless of how good they are. The few times I saw Spiderman on Broadway, almost every child was entranced by the overhead flying and fight sequences.. with the large venues that can be custom rigged in LV, they could even more impressive spectacle.
Baz, a broadway style production featuring the film works of Baz Luhrmann meshed together played for a while recently... I really enjoyed it, and if it were to be re-tooled with a clearer narrative it could work at NWS or in a smaller Bway house.