Al Abut
According to Macromedia's site, UltraDev can be extended [macromedia.com] using Javascript to add support for later versions of JSP. Maybe someone's already written an extension that'd suit your needs, although I couldn't find anything... might be worth a few searches though.
Alternatively, there's a list of other JSP development tools here [jspin.com]
The link to jspin.com was really useful! Do you recommend or use any of the editors they have listed? There's tons of tutorials and I'm going to start digging. I just ordered a book on building ultradev extensions as well, hopefully that will help.
And I posted the question wrong! It's JSP 1.2 that's the latest edition, not 2.0. The servlet spec is up to 2.1 or 2.2 or something.