A new Zune firmware has been released that improves the existing features.

Straight from the update:

This required update will help enhance stability and performance.
For devices being upgraded from Zune firmware version 1.0, this update includes the enhancements provided in Zune firmware version 1.1.

If you are wondering about the process and what to expect, Darius Wey posted an excellent ?what happened? on Zune Thoughts that you should look at prior to updating your Zune ? there is a comfort factor there knowing what to expect!

Is there a difference in performance? Reports are that there is a difference so head over and get your update ?- after you see what Darius had to say though.

Sources: Zune Thoughts and Zune Boards