When a request comes in, and a thread is allocated to service that request, that thread will use up 100% of a core while it is running (unles it has to mwait on somethign such as a database request). Of course, it should be running only briefly (in the 10s of milliseconds). High CPU utilization for a brief time is not a problem. Why do you think it would be? Have you tried running a load test? That is the only way to judge the performance of your system.
By the way, you might want to compare a empty servlet request with an empty axis2 request to see what overhead axis2 is introductiong. I would set up load test for both cases. (I did an empty servlet test several years back and JBoss AS easily served way over 10K requests per second.)