First of all i hope to all the happy new year! :)
So, i has refactored OneInstance plugin (dead with previos year :)) and now where are new plugin caled as subj :) - FileAssociation plugin. This plugin allow you using double clicking on java files and windows open it in runed IntelliJ instance.
This new realization have wide architecture as you can see at http://www.intellij.org/twiki/bin/view/Main/FileAssociationsDev clas diagram for RMI realization. So, i guess, that maybe someone have an interest to add realization of file server to this plugin. For example native windows realization.
This plugin is initial version now, and i hope, with any help it will be increase version number :)