Hi Doc,
Welcome to WBF or have ya just been lurking? It's definitely going to be passive, the subs will be separate options and are not integrated into the 77's enclosure. I'm betting on quasi-transmission line loading. It will be tall and slim and use the triple laminate construction used on all current models except the 33. I'm under oath not to talk about the drivers. Price should be in the high 50's to mid 60's depending on finishes without the matching sub options. I can talk a bit about the new subs since they are no longer a secret. Dimfer has the new SW-15 headed his way soon.
You've got the 7 S2s so you know exactly what the improvements are in the midrange over the S1s. Yup, my system has stabilized now. It took a while to burn in all of those caps and the dreaded Teflon roller coaster ride is now smooth cruising
So much more unforced detail and so much less driver and cabinet coloration. The new Zobel impedance corrector circuits have gotten rid of the minor peaks and dips in FR in the older model when played feistily. In a nutshell, it gets out of the way even better than before. The new midrange also gives a greater sense of punch. Initially I thought the added impact came from the midbass enclosure mods, when I changed driver tubes in the MT amps from Mullards to Teles it turned out to be more of the new midrange. I'm very happy and off the merry go round. I can't fit 11 S2s in my room anyway. It makes the original 9s sound veiled by comparison and is now even more of a chameleon. Downside is that It is now even less tolerant of upstream noise issues. That's where it has taken me a lot of time and effort to rectify things. You know what they say, you get what you put in.