If Vegas is as profitable as you say, and that's commercially sensitive information so perhaps not 100% true unless you work for VS in the relevant dept, why's it still at Gatwick? They flew that route with a clapped out interior for way longer than they should have before eventually refreshing the beach fleet.
Having said that fares are often very high, the market does lay a premium to fly direct and with Virgin, look at GLA and BFS fares, MAN had amways done well too. My gut feeling though is Richard Anderson will ask "How do I benefit from this if I invest $$$$ major money in a fleet replacement?" I might be wrong, but is it a focus they'll want to keep? Probably, keeps their FF base happy just like BA.