Normally, console generations are airtight compartments. Sporadic backwards compatibility aside, consoles are sold as-is, and then iterated with only minor changes like power consumption, size and so forth, without touching performance.
Nintendo actually did something rather new with the New Nintendo 3DS, providing a second iteration of the 3DS with slightly increased power.
During an interview on 4Gamer, Sony Computer Entertainment Senior Vice President Masayasu Ito was asked his take on the possibility of a future release of a PS4 console with improved performance.
Ito-san immediately clarified that he has nothing specific to announce, but the adoption of the X86 architecture, made performance improvements in due time possible. Yet, Ito-san continued, the real question is whether those improvements should be made or not.
With the PS3 architecture and the Cell, it was impossible to expand the machine beyond the capacity of the hard disk. On the other hand, with the PS4 adopting a conventional X86 architecture, it’s easy to achieve flexible performance enhancements while using the same game assets.
That’s why providing a standard performance version of the PS4 and a high performance version of the console side-by-side is, according to Ito-san, an idea that might be considered.
It’s worth stressing on the fact that Ito-san was talking hypothetically, prompted by a specific question. So don’t go taking this as a confirmation a PS4.1 is actually in the works.
It’ll be interesting to see if home consoles manufacturers will consider this possibility in the future, but for now it remains within the realm of pure theory.