Yeah, the MIDI support is bitch on our end, too, in case you missed Ryex's post, lol.
We will likely need to come up with a way to convert MIDI to WAV on the fly.
As for the editor, there is a lot of ground yet to cover. Much of it can get covered pretty quickly, though. There are still some minor details to work out on how some things will function, but for the most part, its smooth sailing. I have the database about half done (I got stalled a bit with this AudioPlayer), but that number is bit skewed. For starters, I was learning Python as I worked for a while, was going slow at it, and was constantly going back to revise code because I discovered a better way. I'm pretty comfortable with the language now, and have a few classes I built to speed things along, so the second half will only take a fraction that the first did. I still have some improvements to existing code that needs done, but more of an OCD thing, not because it doesn't work, so if need be, that stuff can be left for an update (Speaking of which, we still need to make the updater for ARC, but that won't be hard). Other than that, I still need to finish the Database package for the Kernel, which is nothing more than time-consuming and tedious, implement the Action Framework for Undo/Redo, and before its all over, run through the templates file and add Kernel.Protect() to all the event bindings. There are many various GUI things left to make that aren't related to the database per say, but nothing major, save maybe the map editor that Ryex already has a very large start on. I'm sure I'm missing a bunch of stuff, but those are the highlights.