Something I liked.. from the same UI site Legorol referred to: direct links/quicklinks to your own addons ("constantly" visible), sure, the ones with 10+ addons might have issues, but maybe have some priority setting and a cap at ~5 listed? Oh and actually taking you to the page for your addon instead of the edit page might be nice (in order to swiftly be able to check for comments).
Furthermore it's quite tedious to be thrown out to the category of your addon each time you change it's text/update it in some way, either put in a preview option (that'd be awesome) or just redirect back to your addon page after making an update instead.
Summary:
Quicklinks to your addons permanently visible, at least a quicklink to your current addons and/or your portal if you have one.
Update preview/after updating redirect back to your addon page.
Anyways, all in all, amazing work on WoWI, it has at least become my new home
