Next generation's devices will both be desktop PC substitutes. PlayStation PC content will be locked to official hardware only for a year then available on all PCs. Xbox PC will just fully unify the Xbox brand as a PC software platform though it will continue to release games on Steam or other platforms on a case by case basis.
Both devices will be sold as PCs with gaming "modes" and marketed as better and simpler experiences than prebuilts and custom built PCs.
SKUs will vary in price from 750 dollars on the low end to 3000 dollars for the highest specs.