WISHLIST - Saas SCSS
I can't believe I've not found Saas and SCSS earlier. It allows variables in css so you can have a color or font-family set as a variable that propagates to all places in your css file that requires the value. Dynamic CSS basically.
I'm using compass.app currently and it works well. But Web Assist if they plan on doing any CSS related extensions should consider a similar SCSS compiler. That and of course Responsive css features... :-)