Remember guys:
Adding amp and cab sims to this thing = more required processing power.
More required processing power = more expensive selling price.
More expensive selling price = less competitive with other, lower priced, gear companies.
This appears to be a product geared toward the average guitarist who can't afford a $2,500 unit. That being said, I think the FX8 is going to wipe the floor with everything else in its class. Fractal Audio's quality is unmatched by any other guitar processor company out there, and I don't see that changing now.
Down the road, I'm predicting Cliff may include the amp and cab sims in a floor unit (Axe-Fx III all-in-one floor unit, anyone?), but this step definitely needed to come first.