Well the Nextbox will be revealed tomorrow ladies and gentlemen and the rumors are starting to take off like a rocket.
The biggest rumor and question is what if it's more powerful than the PS4?
I say great, more power is always a good thing, but will that hurt Sony? No, not really. It'll give fans bragging rights for the first year or two, but after that it's back to which console has the best games.
One thing to clarify is that the Nextbox will not be featuring a GTX Titan inside the console. The GPU is too big, it would cause significant overheating issues (you though RROD was bad), the price would be over $1,000, and the size of the console will be off putting to many consumers. That being said it is possible to achieve the 4+ GFLOPS that is being hypothesized for the console, and even Sony could boost their performance up to a similar level.
The answer, Crossfire (Xfire).
By running the PS4's APU in Xfire Sony will be able to increase the consoles performance from 4.5x the PS3's up to 7x - 9x (7x = a low of 50% and 9x = theoretical max of 100%), or 2.76 - 3.68 TFLOPS. That's comparable to a low of a HD 7950 with a high of a HD 7970 (both original versions of those GPU’s).
We don't know what MS is using to power the Nextbox, but if they decide to go with AMD's 7970m in Xfire or a custom amplified version of the 7970m then they could very well reach their newly rumored goal of 4+ TFLOPS without breaking the bank or having a 2nd oven under your TV.
Now do I see this happening?
It’s possible, but No. I will say it fits right in line with the expected performance jump from one console generation to the other. Also subsidizing of both consoles would become a requirement to get the console prices down to remotely sellable levels (PC’s and laptops with similar specs. range in $2,000 price range). Sony also said their specs. were subject to change which usually means something could be cut before launch, but this could be the rare case of something improving before launch. Sony also kept secret about the 8GB of GDDR5 RAM from developers, who believe that only 4GB’s were being used, so it’s possible they didn’t know to expect a second GPU / APU to be in a newer devkit.
But that’s all wishful thinking. There’s little reason to really design custom hardware when PC hardware is as good as it is (modifications maybe). So if MS comes out with a more powerful console my guess is it’ll simply be using a modified 7970m which would grant them anywhere from a 10% - 40% power boost over the PS4 (good boost, but not leagues apart). So enjoy your wonderful new semi-custom mid-range gaming PC’s sponsored by Sony & MS, which is more than enough for most console gamers.