iTunes Plus
Looks like the DRM-free music is now available in the iTunes store. An update to iTunes, 7.2, is available now from within iTunes (via the Help / Check for Updates... menu item), and within the View My Account page there's a new setting that allows you to enable iTunes Plus.
There's a setting that enables showing iTunes Plus content, when available. The first thing you need to do is turn it on.
In the Find UI (Store / Search...), there's a new checkbox to search for iTunes Plus music only:
iTunes Plus tracks are marked in search results with a big plus sign:
I thought the price for DRM-free was to be $1.29; maybe in Canada it's $1.39.
I'm very happy they included a way to search for the DRM-free music, instead of having to stumble around looking for it. All in all it looks like a pretty good implementation.