If Casio ever wants to compete with the real high end market, then they will need more then this... The new montage for example has 2 dsp/channel.. Thats a whole 32+ for the whole instrument...
there is a way however to archieve this witouth a really huge investment for Casio, integrating external computer power... Imagine having 32 channels audio over USB(3) up and down to your PC.. Which could give every instrument near limitless access trough a PC program supporting VST effects.... I have said it before, casio has made huge steps and is very very innovative compared to the other bigger names in buiseness... Audio over USB combined with a high end VST wrapper and onboard controll of the (vip) would set Casio ahead of all those others...
but on the current Casio i agree with you that they all seem to be build on the same architecture, and i dont think that leaves much room for expansion of dsp within their current hardware..
maybe if they release the px-7s pro, there will be signs of new hardware, who knows? Only time will tell