But sometimes it is necessary.  We have been busily working on 
separating the extension registry from the rest of the Runtime as well 
as adopting a different *implementation* approach to the application 
model (NO breaking changes).  In addition, as the proposed transition of 
the Equinox project
        
http://dev.eclipse.org/viewcvs/indextech.cgi/~checkout~/equinox-home/transition.html 
progresses, various parts of the Runtime will migrate while others will 
stay behind.  In short we are looking at a restructuring of the Runtime 
plugin along the following lines (this is very tentative)
org.eclipse.osgi
org.eclipse.core.common - some common base support classes like IStatus, 
etc.  We'll look to take into account the JFace uses here as well as 
other.  This will NOT be a dumping ground.  
org.eclipse.equinox.registry - the extension registry mechanism
org.eclipse.core.jobs - job support
org.eclipse.core.preferences - preferneces support
org.eclipse.core.contenttypes - content types
org.eclipse.core.runtime - the original runtime layer with things like 
Platform, Plugin, ...    It will require and reexport all of the above 
plugins.  Make this optional if possible.
This message is only a heads up.  The changes will be prototyped and 
made available for discussion and review.  However, please consider 
these changes when looking to add new API the Runtime as it is today.
Jeff