I never knew this before, but here's a handy plugin debugging trick. If you put a DLL file next to the IDE, then the IDE loads it up as a plugin (assuming that it has a PluginEntry function exported). You can use this as a way to help debug your plugins while they're interacting with the IDE. That's pretty neat!
The other fun trick I recently learned about was that you can add a separator to the Application menu on the Mac by making a new AppleMenuItem and assigning "-" to its text. Sensible, but I never really thought about it before.
It does that with dylibs on OS X as well I think.
That' s been around for a fairly long time.
The advantage being you don't have to go through the step of packaging your plugin into an RBX?
@Mike -- not really. The advantage is that it gives you a definitive place that you can build your shared library to, and then launch the IDE as a post-build step so that you can debug your plugin "live." It only works for debugging the plugin within the IDE, not a built application. Though that does beg the question: is there some sort of similar ability for built applications? Perhaps if the plugin resides next to the executable of the app, then when the app launches, it uses the disk file instead of whatever is built in to it? Hmmm (I honestly have no idea).