People who say there is no frame drops are simply not as susceptible to the drops as others. For example, you can't run the game maxed out with completely fluid framerates. I have the terrain distance turned down to about half, as there's no real visible difference, but the framerate can get bogged down, especially in the Wetlands. Also, in Ironforge with a lot of people running around, the framerate can take a nosedive into the 20s, quite often. You can press CTRL+R to see the frame rate anytime, and you'll see this is true. I run the game at 1920x1200 with everything maxed except terrain distance and AA is completely off. There's a noticeable frame rate loss even with 2xAA on. Again, I will say that no system that I've ever used can run WoW completely smooth, but for the most part, the game does run at 60fps. I choose to have vsync ON in WoW to keep the framerater from going from 100+ frames to 20fps when it drops. That kind of drop is much more noticeable than when it drops from just 60.
Also, everyone on this forum experiences some kind of hard drive caching that makes the framerate go through the floor at times. This is, again, most apparent in Ironforge, especially if you've just loaded the game for the first time. I've got a fast 7200rpm hard drive, and it still caches like a mad-man at times. Again, EVERYONE experiences this. It's all about what you notice or care about...