I have an AudioTron that I still use. It's downfall for me is I can't play my iTunes files. There are products out there that will play the format but not the DRM protected purchased songs. (unless you use hmyn to crack the DRM but that's a little more trouble) It works great for internet radio however.
Apple just announced their Airport Express which is a 802.11G wireless receiver that also has a digital out and you can control from within iTunes. I'll get one of those as soon as it ships since I'm already 'locked in' with my iPod and iTunes purchased music.
That Gateway looks nice if you are also in the market for a DVD player and wireless setup. If you already have the others then it might be overkill.