Hey William!
This really is too much, isn't it! I can't bear it, even though I'm absolutely certain I'm not going to be able to come within missile-launch of affording it!!
My guess, judging by the "hype", is that this is a VSL-authored composition environment/performance tool. Personally, I don't necessarily even think this is MIR yet, but rather that it will "host" MIR, when MIR is ready for release. This would be a bit of slight-of-hand on VSL's part, but would also be a pretty clever way of keeping our focus on MIR, while cooking-up something considerably more "revolutionary" backstage. After all, as impressive as MIR sounds like it will be, it isn't necessarily completely "new", but is rather a better, and more detailed take on something that has existed for a few years now.
No, I'm going with Symphonic Cube and VSL-based "sequencer" -- though sequencer is not going to be the best word for it, I don't think... more like an integrated composition environment. There has been a GREAT deal of hinting going on, particularly in the Synful threads, about VSL's own efforts to match Synful's ease-of-use. If you think about it, the current Performance Tool is actually a very simplistic solution for such a complex library -- so my feeling is that the Performance Tool was just something to get us going, and get people using the library, while they put together their True Solution (Angelic chord -- brass and choir). The library is just too well-conceived for such a basic tool as the current one... There are so many ways that a better tool/environment could be made, and as I say, there's been some serious hinting going on about VSL's work in that direction. I only hope that the "tool" and the Symphonic Cube are not joined at the hip, and can be purchased separately for Toyota-drivers like me!
cheers,
J.