Ok, so you've mastered the HTML spec, your PSD to HTML have reached Pixel perfection and you've even made some great JavaScript applications... But where do you go next? What's the absolute cutting edge? But more importantly, how do you get into it? For example, books on it, communities, tutorials.. etc...
I guess the next step after that would be web programming ... PHP, ASP.Net, Ruby on Rails, or what ever tickles your fancy.
If you're not doing so already, why not read about CSS3 http://www.css3.info/ to see whats the direction for CSS for the near future.
Sorry, in the front-end related technologies like HTML5, CSS3, cutting edge JavaScript, interactive UIs?
If you're very solid in Photoshop, CSS, et al, then Flash would be a good next jump (I did it kind of backwards myself). As always, I prefer to jump into anything with some video tutorials, like those at Lynda.com. From there, I'd locate a couple key communities on the subject, like http://board.flashkit.com/board/ and actionscript.org for Flash.
server side programming is probably the next step. So working with a database such as MYSQL and SSL's like PHP, Coldfusion, ASP, etc. Or have a look into AJAX.
Jquery would be good. You don't need to spend any real time to do some solid things with it that will improve the usability of sites (tooltips, scrolling stories, link effects, etc).