It hasn’t been given any coverage yet, but AppleScript has had some work done in Mavericks. I’m not sure when the release notes and updated ASLG will be available, but you can read about the changes here:
macosxautomation.com/mavericks/libraries/index.html
The three biggest changes are probably the new “use” command, the semi-optional new handler syntax, and the introduction of script libraries. In particular, script libraries can be written in AppleScriptObjC, meaning anyone can use it in their scripts without the need for ASObjC Runner or other workarounds. This is pretty cool stuff.
On a more commercial note, I’ve released a new app, ASObjC Explorer for Mavericks, designed for writing and editing such libraries. I’m also hopefully only a few weeks away from releasing a new book, ‘Everyday AppleScriptObjC’, covering the topic. You can read more here:
www.macosxautomation.com/applescript/apps/
And for those not moving to Mavericks, or who also need to support pre-10.9 users, the price of AppleScriptObjC Explorer, which runs on 10.6 through 10.9, has been slashed.