Unregistered,
misconfiguration, I am not aware of any converting that goes on, but I've included a screenshot of the profile editor, where it allows you to choose either or. During testing, I used ALSA and had no problems at all. I listened to music pretty much throughout all of the testing, without any issue that I recall.
As for high-res gaming, it seems to be great to me. Granted, I've only used a couple games, and plan to use more in the near future. In the case of both games that ran well (NFS: Carbon and Guild Wars), I maxed out their graphic settings and both ran just fine. NFS ran the best though, without any noticable lag. Guild Wars did lag a bit, but still ran relatively smooth. It could also have lagged due to other processes running in the background (main PC is only single core still).
I was actually impressed quite a bit by the performance, because I expected a massive performance hit as well. In the future I'd like to do some light performance comparisons, but as far as I know, there is no easy way to benchmark those two games, or WoW, under Linux.
I don't think you'll be too disappointed, especially with WoW. There are -many- WoW players who use Cedega and I've never heard much bad about it. This is where I think Cedega should offer a free trial to their program. I think it's ridiculous that they don't. They used to, but I am not sure what happened to it.
Regardless, if you are interested a lot with WoW performance specifically, you could peruse the
forum and read up other experiences.