Why develop it further when they their Elation brand has a more mature and more developed product?
My take on MyDMX is that it's got a lot in a very cost effective package as it is. But many people here come looking for a very inexpensive solution for their complicated desires. Sometimes it's really a matter of "right product for the application". Sometimes it's MyDMX, sometimes it's Compu Live.
I'm not here to take cheap shots at forum users or MyDMX. I have MyDMX, and for what it is, it is ideal for my application. My application is mainly needing quick access to a vast number of scenes that I am still developing, and be able to hand off light duty to some crew person who may not be a lighting person. "Click the buttons on screen, I think you can handle that..." is my application.
My take on MyDMX is that it appears to be scene based, which is all well and good. it does let you do manual overrides, but doesn't do so via a joystick control. That would require a selection function(select fixture), plus a custom mapping procedure that would have to be done on a per fixture type basis, PLUS acacept joystick input. ANd where would it get joystick input from? The game port or the USB, or does it get this from Windows itself. Or even a joystick icon? Or some combination?
Not discounting your idea, but for what MyDMX is, it's really more suited for a higher level product.
Lighting consoles are designed to be very open ended, so assigned a joystick control function typically isn't a big deal once you've told the controller what you expect out of it per fixture. With software, it's not quite so simple.
Think of the target marketplace which is mainly DJ's looking for something perhaps a tad less intimidating than a decent console costing around the same price bracket. I think for whom they are marketting it to, the product is ideal. While I'm not a DJ, I just need quick access to stuff and I don't like to memorize much of anything, so MyDMX becomes an ideal addition to my sound production company.
In the meantime, do feel free to hijack any fixtures in a scene. MyDMX should allow that, provided they aren't already controlling the fixture actively when you wish to make your changes.