I must preface this by saying that Sony needs to be wary of over-hyping/marketing the PS4 Neo as something new/different. If they try to segment the market, I think they can hurt themselves. I believe the PS4 Neo shouldn't be sold long-term alongside the vanilla PS4, but instead be the new default model (like slims replacing fatties in gens 6 and 7 more or less).
Due to new lithography and process technology, the Neo shouldn't be any more expensive to produce in comparison to the vanilla PS4, and in fact, it would be more expensive by quite a lot to continue producing both models. Neo should just slot in as a direct replacement at the same price within a year AT MOST, and hopefully more like 6 months or less to clear residual PS4 vanilla stock. Keeping the fabs running for the old 28nm stuff, or creating a new die shrink and running seperate lines for vanilla PS4 APUs would be stupid, wasteful, and more expensive than just transitioning the entire production process to the new standard Neo model. A 'premium' vs. 'vanilla' dual-offering would just put a bad taste in the mouths of consumers, cheapening the brand appeal rather than enhancing it.
The frankly wise decision to not make Neo-exclusive games just seals the deal. Over-hyping the Neo would just fragment their 8th gen momentum, risk alienating the ~40M vanilla PS4 owners, and in general be a bad strategy. Better to focus on continual software rollout, VR support, and competitive pricing.
----------
Now, as long as Sony doesn't choose the wrong path in PS4, and I don't believe they will, I do predict that :
By end of gen the PS4's Neo revisions alone will outsell the entire X1 cumulative sales from launch to EOL.
