In addition, we've added the ability to permanently disable
annotations.

Even though we think annotations are really cool and give you yet
another reason to start interacting even more deeply with videos on
the site, we realize some of you are "old school" and prefer to see
just the video and nothing more. For this reason we've added a setting
that lets you permanently disable annotations.

Check out this forums post for more information.
http://help.youtube.com/group/youtube-feedback/browse_thread/thread/3...

We've also updated the content in the Help Center to reflect this
change: http://help.youtube.com/support/youtube/bin/answer.py?answer=92712

G'day,

Timmy