Following the instructions in http://www.intellij.org/twiki/bin/view/Main/PluginTesting I could not make either solution work.
It seems that at least since build2226 (I did not go back further in time) idea.plugins.path is no longer used to get to the plugin directory. The intereting thing is that both config and system directories can be overridden from the command line through idea.XXX.path...
Even more weird is that from the command line it seems that IDEA add the plugins in the directory of idea.plugins.path since I am getting a bunch of name conflicts on things that are defined only one in one directory. However the lax based launcher just stay oblivious to it, it seems. No name conflicts there!
Anybody has seen this? Any clue of what I might be doing wrong