That Vegas was busy this last weekend isn't really any kind of indicator of a good economy. Vegas is ALWAYS jam-packed over Labor Day weekend.
That subgroup of Vegas visitors who are willing to pay the astronomical prices that Vegas charges on busy holidays weekends are largely immune to whatever happens to the economy. I've been in Vegas during economic slowdown times, and overall visitation went down, but the really busy weekends were just as frantic as ever. If you're price-sensitive, you won't come to Vegas when its prices at at a stratospheric peak; therefore, if you do come then, and pay $300+ a night for a room, etc. etc., price must not be a factor in your decision.
I am in Vegas now, and I'm paying $64 a night with a daily $40 food credit. The same room I'm sitting in now was $299 plus resort fee over the weekend.