Well currently I have 200+ custom pages - these work well except for the following issues...
1) Both the script and template/default have a lot of extra files within them - it would be nice to be able to specify a separate folder to keep these separate from regular template and scripts
2) It would be nice to be able to specify a unique header/footer for any given custom page
3) It would be nice to be able to specify no sidebars for any given custom or indeed other page
Currently the only place I can use a custom header is in forums - it is not possible even to use them in categories

, but to be able to have a greater control over custom pages would be good.
Maybe even a system to avoid having to create 3 files per page (I will be growing these custom pages to around 600 this year, so those directories will get rather large LOL )
I think the ability to increase sites beyond the forums would be great for many sites, whilst keeping the overall feel of the site.
I am trying to cater for people who do not like forums and will never visit a forum - which is great if they can come to the site for something else. I am not worried if they never visit the forum LOL