Some background: Michael and I were sharing thoughts about the portals package and it turns out that we both would like to see it enhanced to the point where it could be used to build many of the pages in a simple site (maybe all of the pages).
ACES does this (and was the starting point of our discussion) within the constraints of the existing portals package (in it's 3.4 form). But it's limited by the fact that the customization options are limited (i.e. title bar color and a couple of other things) and that customization options are at the portal, not portlet, level.
A limited expansion of the capability of the portal package could greatly increase its usability.
Read Michael's roadmap proposal and comment away!