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.
Yes, by default only 1 instance of each Servlet exists in Servlet Container and serves multiple threads simultaneously.
If SingleThreadModel implemented, there are 2 options: 1) create pool of servlet instances and pass new request to new instance 2) serialize incoming request and put it in the queue to one servlet instance
1), or 2) - depends on servlet container implementation.