I believe that MLB and NBA will come to Vegas in the future too.
Here are my prospective names for each team:
MLB: Las Vegas Martians
Area 51 is very close to Vegas, and the name Martians would be fitting given all the legends surrounding Area 51.
NBA: Las Vegas Bonanza
This team would have an overall Western image for its branding, including naming itself after the second-longest running TV Western in history, a show that was set in Nevada. The show's theme song would be the theme song for the team as well. I originally wanted the Bonanza name and Western theme for the NHL team, which would have encompassed the TV theme being used as its goal song.