I've got problems getting the new Modeling plugin v101 to work.
I use Flash Builder 4 premium with a plugin installation in a new Eclipse 3.5 JEE edition on Windows Vista SP 2.
I downloaded the new Adobe_Application_Modeling_plugin_v101_eclipse35.zip, extracted it and put its contents into the /dropins directory of the Eclipse installation that hosts FB4 (so the /plugins folder of the Modeler stuff resides inside another "Adobe_Modeler" folder inside the /dropins folder)
After starting Eclipse, the plugin does not seem to be active. Neither the "Edit Active Data Model" button shows up in the Data/Services view of the Flash Builder 4 persepctive, nor do I see any new perspectives / views when opening the corresponding dialogs in Eclipse (Open perspective / Open View). Also, when opening the "About Eclipse... / Installtion Details / Plug-Ins" dialog there's no indication that the Modeler plugin was loaded...