Hello! And au contraire: Las Vegas has a long history of swim-up blackjack, thanks first to the novelty floating gaming tables and poolside slot machines introduced briefly as a publicity stunt by the Sands back in 1954, and then made a permanent fixture -- with accompanying cocktail service -- first by the Tropicana, then the Hard Rock, and most recently the Fortuna Pool at Caesars Palace, all of which offer cocktail service.
In addition, if you just want to drink but not play, the European Pool at Encore has a swim-up bar that's among Fodor's top picks in the world for swim-up bars (as is the Trop's). The European Pool is the topless one, so it's adult-only as well as being hotel-guest only, however. Also, cocktails are not served in the water here; you can swim to the bar, which is in the middle of the pool (similar to the setup at SLS, we presume), but you need to get out of the water in order to order a beverage at the bar or hit the gaming tables here.
These are the only swim-up options we're aware of, but at the party pools it's not uncommon for servers to bring drinks to those in the water. We don't think this service generally stretches to the level of attentiveness shown by this waiter at The Dunes back in 1955, who is actually in the pool, in uniform, serving breakfast to a guest.
