A software update for the Zune has been released today. Zune users will notice additional games a Zune Social refresh and incremental improvements on the software. From ZuneInsider.com:

On the games front, we are giving away three new additions,
Checkers, Sudoku and Space Battle, plus a new multiplayer mode and
single player difficulty levels for Texas Hold’em.

The team also did some great work the Zune Social visual refresh to
make it easier to navigate, as well as adding a new feature called
“like minded listeners,” which will let you see how compatible your
music tastes are with other listeners and friends.

On the more techie side we focused on improving overall stability
and performance in the Zune PC software and device firmware, such as
improved play count reporting and content synchronization between the
Zune software and the Zune device.

link - Zune 3.1 Update News