When people compare XSLT to JSP and say JSP will be replaced by XSLT, they are just comparing orange to apple. Sure, XSLT and JSP are all capable of generating HTML for presentation, just like oranges and apples are all fruits, but they have really distinguised features or nutrition serving for different purposes. XSLT and JSP will coexist just like oranges and apples. You will pick one of them mostly depending on what features that you need.
To me,
(1) XSLT is the query and formatting tool for XML, just like SQL to relational data base.
(2) JSP on the other hand, is like a 'glue' to stick things(Static content and dynamic contents in many forms) together
When it comes to presentation layer, they do compete with each other in some circumstance, like presenting the query result in HTML format. You do have the choice to encapsulate the query result as a bean and use JSP to present it, or use XSLT to convert the query result in XML format, which can be generated in native SQL with newer release RDB, to HTML. XSLT will be used more and more in this kind situation.
But things are not always that straight forward. Unlike what is illustrated in the diagram of the article, the model should include both the data model, and business model(Action classes, which should not be in the controller part as in the diagram, EJBs etc). Of course, these all can be mapped(or bound to) XML and then use XSLT to combine them and transform into HTML(Multiple passes are very likely). But in many cases, it will be more effective to use JSP to glue them together and emit the HTML directly.
Even if XSLT would gain all the ground in presenting the result(or generating HTTP Response), JSP is still needed in helping the form beans to capture the data from the form, fascinating the processing of HTTP request etc.
As far as the performance and productivity go, JSP are still ahead of XSLT, at least for now. Debugging a XSL style sheet is much more difficult than debugging a JSP, and JSP page compiler definetly has smaller footprint than XSLT engine and parsers. Anyway, JSP can be (and was designed to be) used by web master. But I really don't think XSLT can be used by a non-programmer effectively unless some kind of tools are developed for that purpose.