For me, the most frustrating thing about using MS Office is Clippy (I know, I know, I have a high frustration threshold). Clippy is the animated paperclip that's been Microsoft's way of providing users with (a little) assistance and (a lot of) annoyance ever since Office 97. On its tenth birthday this year, Microsoft has finally put Clippy out of his misery, leaving him out of Office 2007 (and Vista) altogether.
Apparently the goal wasn't so much to kill Clippy as to have a single way for users to find help, rather than including menus, toolbars, and an animated office assistant. Whatever it was, I'm just happy the irritating little twat's gone - hopefully for good.
Thanks Zoe, for alerting me to this joyous news!