The site is kinda sparse on details so far - Wondering if the 256 is going to be along the lines of the initial C-One concept where it would have something like a Monster SID (multiples of 3 voices) and a Super VIC (massive resolutions, copper list, etc.)
These were the Specs Jeri Ellsworth had hoped for initially: http://c64upgra.de/c-one/s_specs.htm
Unfortunately costs/manufacturing decisions curtailed much of that.