I posted our goals for Rico on the Rico Blog.
A quick recap:
Goal 1 - Stay out of the web developers way.
Goal 2 - Keep it simple.
Goal 3 - Pleasure to use.
Goal 4 - Should work well with the simplest of technologies.
Goal 5 - Should be easy to expand.
Goal 6 - Should be inovative.
Goal 7 - Should complement not compete.