Is JSP a whole 'nother animal when it comes to Java?
Not really so. If your understanding of core Java is good JSP's should not be a problem. You need to understand the life cycle of a servlet, servlet context , sessions, and other topics related to servlets which you will use in the practical world of indutry programming and since all of it uses concepts based on Java you should have absolutely no problem. JSP is as simple as HTML programming with a lot of what you want to do available on the internet. Buy the Head First Java Server Pages and life will be easy while dealing with JSP's. On intellectual aspect of learning JSP's I would rate it as a High School level course.