Buy PS4/X1 now, or wait for NX?

[SuperNova]

I'd recommend getting a ps4 for third party.
I wouldn't worry too much about publishers skipping the current market leader and media darling Playstation over industry unfavorite Nintendo. Publishers are not going to skip over a likely 40m+ and growing userbase (depending on when the NX comes out) even if the NX should be stronger than the PS4/Xone.
We don't really have any indication of how strong NX will be, or hell, even what it will be, and don't know how good it's third party support will end up being either.
PS4 on the other hand will get any third party multiplat offering out there and you will likely get slightly better performance out of it compared to Xbox one.
And in case I'm wrong, you can always get an NX later down the line, but you will have instant access to all multiplats now.

Unless you really need an NX at launch and don't have the funds to buy a 299,- Ps4 now, and another (probably similarily priced console) one or two years down the line, I'd go for the Ps4.