Servlets are an easy, extensible, platform-independent way to do the same thing, and it is about an order of magnitude faster. For example, we wrote the Java Web Server using the toolkit. So it is a server development platform. It does not contain ways to remote objects like RMI does. The Java Servlet Development Kit is being rolled into JDK TM 1.2 as a standard extension.
Standard extensions are APIs in javax.
So you can expect to see javax.servlet. So to answer your first question, JSDK will be updated as frequently as the JDK moves forward. JWS is one such server that we built. So JWS will inherit all the functionality of JST and then its own HTTP web server specific functionality to it. We are still debating what kind of HTML generation support we should have.