I listened to (and watched) the Sonic TALK 469 Korg's Big Announcement Podcast.
While they don't reveal anything per se regarding the upcoming Korg announcement, the fact that Nick got contacted by Korg is telling in itself, in my opinion. Nick usually reviews synthesizers (keyboard and/or modulars/modules) so the fact that Korg offered him to sign a NDA to learn what it is tells that it's likely an synthesizer/keyboard of some sort.
Also, Non Eric talks about the possibility of it being an upgraded Minilogue with more voices and a couple of more features and makes an comparison, feature wise, between the Roland System-1 and System-8. I'm probably reading a little too much into this but I think I see a hint of a smile when he says talks about the possibility of an upgraded Minilogue, making me think that he might actually have taps on that it is indeed a big brother to the Minilogue.
Thankfully, the first of November isn't that far away so we'll all know (hopefully) pretty soon. If I was to wish: A full size key bed, building on the Minilogue foundation would be very nice!
/End of Speculation