This week's giveaway is in the EJB and other Java EE Technologies forum. We're giving away four copies of EJB 3 in Action and have Debu Panda, Reza Rahman, Ryan Cuprak, and Michael Remijan on-line! See this thread for details.
No, static variables aren't serialized. Like Stanley said, first z was 9, then the code incremented it, so now it's 10. If you remove all the code which serializes and deserializes objects from that example you will see the same thing happening.