Ooh! Get in on this one quick. A new language called Curl, with Tim Berners-Lee (like, the inventor of the web...) as a founder. It's sort of DHTML, but as a single language, without the mess of JavaScript and HTML and other technologies, and it's also got significantly greater capabilities, more along the lines of a programming language than a scripting language. From what I've seen, I like this a lot, and so did some other people.
The downside is it needs a plugin to operate: this severely limits the penetration of the technology. However, the same was initially said about Flash when I started using it (way back when it was still called Splash Animator); all it takes is for the dominant browser (then Netscape, now IE) to pre-bundle it, which they'll do if they have any sense at all. This could be good.