Roland has hinted at an "upgrade" from the original Jupiter-8. I suspect its not a new product line and I am guesing that it will not compete against the Fantom G. It will likely be:
-Multitimbral Synth Engine (high powered V-synth)
-Auto-tune & Vocoder builtin.
-Substantial Pianos / Orchestral sounds builtin or something with a sample set like what AX-synth has.
-Built for live performance, with multi d-beam, and touch pad matrix, and knobs.
It is obvious Roland needed a product that is more oriented to synthesizer music with extra features for a long time, kind of like a V-synth that goes beyond the scope of its purpose. I'm sure it will also be missing something obvious so that it doesn't retread on another product that is currently in existence, like the Fantom G or V-synth GT. They wouldn't cannibalize those products again, because the new Junos already do that. They also would not kill the V-synth line by including all of its features, so it is likely not to have the same structure.
we will find out soon....