Most of the reasons for switching to Java aren't nearly as compelling for users of OpenACS (integration, sales, marketing, speed, etc.) If you can get 4.0 TCL feature-complete, there's no great reason not to stick with it for a while, unless you are highly concerned about worldwide adoption (the "TCL's ok" argument is likely to be harder to make to new users with aD and Vignette switching to Java). I suspect most people here are more concerned about getting their jobs done, however, in which case you would generally stick with what you know until there's a compelling reason to do otherwise.
