I know that this was probably suggested before but the feature I would like to see the most in next realease is a nicely done RSS and ATOM Feeds, with options like what to display bellow pictures etc. I know there is some plugin for this but I think this is the option that should be part of the package becouse most script for publishing any kind of content already have it.
already in the devel code for cpgNG - rss feeds definitely will be an important feature. Not sure if it will go into cpg1.5.x as well though, maybe you'll have to wait for cpg2.x