If you like long lines and disappointment this is the place for you.
As a minor fan of the show I decided it would be pretty cool to stop by and check the place out. The show is pretty interesting, (even if it is mostly faked and scripted) and being a Vegas local, I thought it would be a cool pay to kill a couple hours.
I rolled up around 2pm and saw a line of tourists which wrapped around the store. The store front itself looks just like the one on the show and has no mention of Pawn Stars. Fortunately, the line moved quick and I got in within 20 minutes.
The shop itself was very small and somewhat unkept. Random things were piled behind the counters. Looks like they don't care to keep it clean when they aren't filming any episodes. Like a few other people mentioned, there really isn't much for sale. In fact, the interior is like a typical pawn shop, few weapons, jewelery, instruments and the like. If I did not go in knowing that this was the Pawn Stars shop, I probably would have thought it was just another generic pawn shop.
They didn't have much in the ways of cool and exotic collectibles or rare trinkets. They did have a pretty big section for souvenirs. Though I would hate to admit it, it seems more like a tourist trap. Get in, take a few pictures, move along,