Definately there is a need for OJS/OCS integration (for example, the entire login/user module).
At the moment the only solution I have managed is to join OJS / OCS and a CMS (Joomla) together.
It's a bit tricky but what I get then is control over every single menu item in all three platforms, which I can use the Joomla ACL functions to control. So I can mix my OJS and OCS menus if I need to into one menu block. (My papers, My conferences, My profile). If I have a conference organiser who will publish the papers in an OJS journal after the conference, I can give him/her access to the editorial controls in a single menu block as well.
The good thing is the entire core of the OJS and OCS do not need to be touched, it is all done through template hacks.
My most recent project is http://www.gamblingstudies.org
where they have a conference coming up (OCS for the submission and Joomla CMS for the informational part), a best paper submission (OJS submission) and a Call for papers for an upcoming Journal issue. Later we will add a public forum for the papers (either a forum like this one - PHPBB or a joomla forum addon. We maintain as much as possible a single template look by using Joomla templates and taking the main template.css information and making that the css for the OJS and OCS as well. Not perfect, but it pretty much works!