If there is the a ride, I had better contact my buddies at IF or Ellsworth to kit me out!
Not specifically a WW ride, but the last few years on Tuesday morning, Scott USA has held a group road ride that starts from the Dirt Demo site, runs though Boulder City and out to the state park at Lake Mead and then returns offering some nice roads and a few elevation changes.
Also, while not ideal for those who are going to have to spend the whole day in the booth but last year I got in some early morning ride with Las Vegas Valley bicycle club on Wednesday and Thursday mornings. Start time was ~6:00 am both days with Wednesday being a semi-casual 30-mile ride through several scenic (and hilly subdivisions) on the far west side of town and Thursday was another ~30-mile cruise that included a lap of the scenic loop at Red Rock Canyon (traffic flow is one-way only) which includes a couple nice prolonged climbs and then a fast descent once in the park.
The USA Criterium World Criterium Championships is also making a stop during Interbike with the final to be held durign the evening of September 27th and at 8:00 pm, just prior to the men's final, the promoter is holding the Industry Cup Challenge critierium which is open only to Interbike Exhibitors!
the evening of September 27th but I am lead to beleive that