The Las Vegas Strip, home to themed casinos that mimic the canals of Venice and the skyscrapers of Manhattan, is getting a new events center modeled on an Eastern European glass factory. The Cosmopolitan of Las Vegas is developing a 3,000-capacity theater that has sat empty since the hotel-casino opened in 2010. The auditorium is expected to open by the end of the year and cater to conventioneers, boxing fans and concertgoers.