Tia, try clearing your battle.net cookies, that usually works for me.
I'll look at your graphics settings later. For now, I'll note that if the pipeline is optimal, with uncapped framerate (including no vsync), either a CPU thread or the GPU will be at 100%, and depending on graphics settings the other one will be close to 100%. If it's a CPU thread that's at 100%, you can get higher framerate (and higher GPU utilization) by splitting that thread up into multiple threads, when possible (if the GPU is at 100%, all you can do is improve algorithms, get a better GPU, or get more GPUs).
If WoW is now more optimal, then that's great, it just means you may have to be more careful about what you cap your framerate to if your system has heat issues, but you should be able to get higher FPS or more detail now than you did before, if that's what was going on before.
Under optimal circumstances I don't think anybody should game on a mac, and I don't think anybody really buys them for gaming. But many for many reasons, that is what many people have to do. Maybe they have to use Mac's for their profession, or maybe it's their family computer, or maybe some one gave it to them as a gift, et. al. And just maybe, they can't afford another computer exclusive for gaming right now.
Total nonsense. I'm on my 6th Mac (not including work). My first was a Lisa, one was an APC, and each one was easily on par with what I could buy at the time for the same price. Each has also had a much longer useful lifetime than if I had gotten a cheapie DOS or Windows machine.
Under optimal circumstances, game makers would make more games for Macs. I mean, wouldn't it have been awesome if Bungie had been able to get Halo to work on Macs? I guess it was just too difficult, though, so they had to make them Windows-only, just like that earlier game they made, Marathon. I remember wishing I could play Marathon on my Mac II. Oh, wait, I could.
I see that finally there's an all-in-one that pretty much matches the iMac, and at a pretty good price (from Dell). Not sure how much better a retina display is going to be, 2560x1440 at 27" is pretty sweet, but maybe they'll also boost the graphics and CPU speed. Maybe they'll improve the cooling while they're at it!