I think anyone who uses framwework builder will have to say its an excellent tool but for many it is not used as I am pretty sure many do not really know how to use it or the benefits.
This is especially so for Dynamic themes. I have used them on test sites and they are brilliant for skinning sites but even I would love to see WA do a detailed tutorial on how to best use Dynamic themes for skinning a site.
Whats the best way to add new themes later on
What is the most effeciant way to set which theme to use on a site possible using an admin setting.
This list could go on quite a bitbut the to unlock the true potential of framework builder is something that WA should encourage as this is one of the best gems produced by WA.