I posted this info in another thread, but in summary, my understanding is this: the Virtuoso power amp is finished and available for purchase right now. The Virtuoso pre-amp is still being finalized but will be available very soon.
My understanding also was that these will be followed by a "blending" of the two into the Virtuoso Integrated (which was supposed to be coming first, but is now last, for a variety of reasons), and only then the Aria Signature integrated.
But perhaps the A.S. has leapt over it in the order of production. We shall see. I also don't know to what extent the A.S. might use trickle-down from the Virtuoso, or to what extent it is a beefing up of the already excellent Aria line (preamp, stereo amp, monoblocks).
I know at least one member of A'gon has a Virtuoso power, but so far hasn't reported back on impressions.