Late last night/early this morning Apple pushed out an update to iTunes via Software Update, bringing it to version 7.2. The only obvious change is support for "iTunes Plus," which is apparently what Apple is calling the new DRM free $1.29 tracks announced back in April with EMI. The "What's New" section of the iTunes 7.2 Help includes this line: "With iTunes 7.2, preview and purchase iTunes Plus music-new higher-quality, DRM-free music downloads from participating music labels." As of this writing, however, the iTunes Store does not appear to have been updated with the DRM free tracks; presumably this will be forthcoming shortly.
Thanks to everyone who sent this in!