Despite the fact that lots of of us really wish MS Office (Word especially) would die a quick and painful death (iWork and Pages people, or better Scrivener from Literature and Latte), when there are updates to MS Office you really should update:
Microsoft says the update provides the “latest fixes to Office for Mac 2011. Additionally, this update contains stability and reliability improvements.”
By and large this is true for most apps today. Updates don’t just fix bugs or add features, they also can fix security problems.
Don’t ignore updates!