The basic migration process from the 1.5 Component to 1.6 core com_content is almost finished! A demo site[1] is now available with joomla 1.6 installed, where you can test in the backend the revision control functionality.
These adjustments have not yet been commited to the trunk (a patch is available[2]) as they need to be revised and maybe modified - this is where you can contribute! Test it and give us feedback! You may also install it on your local machine with this archive [3].
Preview images
You may access Revisions view from the main view
You may enable/disable and configure revision control through the Options from the articles view toolbar
Most of the features (excepting mail) available in the 1.5 Component are now available and enhanced!
The next step in the development is concurrent editing, along with autosaving. A more technical description is available here [4] and you can also follow me on twitter, for updates [5].
[1] http://rosedu.cs.pub.ro/~victorc/trunk/
[2] http://rosedu.cs.pub.ro/~victorc/trunk/trunk_revisions_31_07_2009.patch
[3] http://rosedu.cs.pub.ro/~victorc/trunk/revisions_trunk.rar
[4] http://groups.google.com/group/joomla-dev-cms/browse_thread/thread/41ad3a362a810a44?hl=en-GB
[5] https://twitter.com/vcarbune/