Omid,
The class file is being copied to WEB-INF\classes\blah in the tomcat webapps folder. I was under the impression that this would hot deploy.
Hot deploy is a two-step process… the first part of the process is to have MyEclipse get the file out to your application server (which it is correctly doing) the second part of the process is to make sure you have Tomcat (and/or your web application context) setup correctly to recognize and reload changed files. You can use the Tomcat administrator to check the settings of your web context, also please refer to the Tomcat docs for setting this.