For yourself, if you want to keep current to be able to support users, it might be a good idea. I am running Win 8 for that reason, (and oddly, I kind of like it.)
We advise our clients that there is no need to upgrade Office when new releases come out unless there is a new feature that will make the expense worthwhile. The changes are usually minimal and really, how much can they add to Word or Excel?
If you are rolling out a fleet of new machines that come with it pre installed, which we discourage, then you might want to upgrade older machines to keep things consistent.