AppleScript Changes in iTunes 4.8
iTunes 4.8 was released on May 9, 2005. New features include support for transferring contacts and calendars from your computer to your iPod (under Mac OS 10.4) plus other enhancements with regard to the iTunes Music Store.
No AppleScript enhancements or fixes, but...
iTunes 4.8 introduced the ability to sync calendars and contacts to the iPod. Previously this was done manually or via iSync. These options are new and available in the iPod tab of the iTunes Preferences. Also, a new option in Advanced Preferences allows the user to play videos in iTunes main window, a separate window, or in full screen. These new features, like all of iTunes' other Preferences, are not scriptable. Interestingly, it seems as though some QuickTime Pro video-play-abilities are now available through iTunes.
Two GUI notes: the "Script" menu icon is now black, like the Scripts Menu icon, and a new QuickTime button appears at the bottom of of the browser to allow full-screen playback of QT movies.
Movies downloaded from the iTunes Music Store or dropped onto iTunes behave just like audio files. (Note: not all QT movies are playable in iTunes; apparently just MP4s and MOVs.) They are added and listed as tracks in the iTunes library and have accessible tags. They are listed with a movie icon to the right of their names. They are AppleScript accessible and their kind is "QuickTime movie file". The actual files are stored like audio files, using artist and album tags for folder configuration, and are prefixed with "Video-" in their filenames. As far as the new "Play videos" Preference, "main window" means the Artwork pane; "separate window" and "full screen" are, well, obvious. If you click (once) on the Artwork pane while the vid is playing, it will open in a separate re-sizeable QuickTime-like window.
(One thing I noticed, and which may be obvious, is that a video's Artwork doesn't exactly work like regular Artwork, and I expect to delve into that AppleScript-wise at some point.)
Several Correspondents have pointed out that you can now "Check selection" and "Uncheck selection" by Control-clicking selected tracks and clicking the option in the pop-up. A mix of enabled and disabled selected tracks will provide both options.
iPod filenames no longer use the actual filename of an audio file. Filenames on the iPod are now rendered as seemingly-random four-character uppercase combinations with the file's honest-to-goodness three-character extension. Thus, you'll see "JPIT.m4a" and "ZEUS.mp3" and things like that inside the iPod's "F" folders. This isn't a big drawback since iPod uses the ID3 Tag data for organizing. But it does make locating a particular file on your iPod just a tad more difficult. Try using Show iPod Song Files which will show the files of the selected iPod tracks in the Finder (a la iTunes' "Show Song File" menu command) .