ProAnimator is a standalone application for Mac and Windows, as opposed to Invigorator, which works inside of Adobe After Effects. Both aps are great, and as you may know ProAnimator has some very powerful motion controls, which are not available in the current versions of Invigorator. You can, however, render out movies with alpha channels, which you can further manipulate in After Effects.
In answer to your question, I know for certain that ProAnimator and Invigorator are both are being developed further by Zaxwerks, but can't speak to which elements from ProAnimator may be built into Invigorator or when that might happen.
I can tell you that I was working with a pre-release version of ProAnimator 4.0 at NAB this week - and it ROCKS!