YUI 3.4.0 is to be released shortly.
Drag Drop features does not work in IE9 (backport yui 2.9.0+3.4.1 from master)
META: Major new features for Moodle 2.2
Regression: HTML of currently launched/active SCO not rendering correctly in the TOC.
YUI2&3 upgrade META
import latest yui 3.4.1pr1 into master for testing