Nope, wont buy.
I love Sony. I love Playstation. But i dont support the idea of upgradeable consoles, or 0.5 consoles mid gen.
And to be clear, im not cheap at all. But this is in my opinion some bullshit if true, which as of right now it is nothing more than a rumor.
It goes against the nature of consoles, which is the standardize (does this word exist? LOL) of every unit for all users to ease the process of developing games.
I would prefer to pay a high price up front from the launch (600-800$) and keep the same unit for 6 years, than paying 400$ and then 3 years later have a beefed up version of the same console for whatever price.
I play on consoles because it is a straight forward platform, i dont like PC and will never have a gaming rig. Unless the videogames panorama change drastically and HAVE to buy a PC in order to keep playing (streaming games for example).
EDIT: If there is in fact a new version of the Ps4 with an HDMI 2.0 and some other improvements not relative to the videogame processing specs, i wouldnt mind at all.