What are the types of things Sony could do to the PS4 that would make you not buy it. 

I'm dreading the fact that they may go motion controls, if they try to pull something off like the Wii...I dunno what I'll do. I want my controller with buttons.

Really? I thought it was a brick with batteries that people waved around at the screen.

Not "want" you say... well it would just have to have a poorer library of games compared to it's cost than the next Xbox. Unless they price it at £500 and the Xbox is £250 I am doubtful that will happen though, because Microsoft doesn't really have any first party games whilst Sony does have at least some desirable franchises.

Your question in the body of the OP is different though, there you are asking what could Sony do that would make me not buy it... for which the answer is price it above £100-150 (where it lies in that boundary will depend on how much the Wii U is) There are other factors of course that may move the price limitation, or something like anti-used game tech/always-online bullshit/subscription for online would probably put me off entirely. This is still assuming the PS4 has a half-decent game library.

As it is I currently have no plans to even buy the Wii U, but if I do decide to join the 8th gen most of any decision I make regarding me buying the PS4 rests in Nintendo's hands... in other words Nintendo will have to really screw up the Wii U for me to look at the PS4 first.

I think it's time for systems to have almost no load times. If the games on the PS4 require an install, there should be barely any loading. Even when some games on the PS3 installed, there were longer than average load times. If the console has long loading, I won't buy it.

Call me picky, but I feel that once a game boots up, it should be smooth sailing from there on.

To set the record straight I've played all the popular Wii games...no interest.

nothing since i wont be buying one regardless. ps2 and ps3 were all disappointments for me.

no no no it's a brick with batteries AND buttons that people wave around at the screne, kinda like that thing (can't be arsed to remeber the name) Sony made a few years ago that hardly anyone wanted or cared for

-do a wii

-charge for online

-go on a Nintendo/Microsoft software release routine

-stop making new ips (which kinda goes hand in hand with the 3rd option)

Change the button layout on the controller...hell, change the controller at all. I can't stand the Xbox layout. It boggles the mind why some people like holding their controller cockeyed. The PS3 controller is perfect.

make it over £350.
Close Naughty Dog
No Uncharted 4
No NEW ips at release. (I'm looking for 4 new exciting BIG NEW Ips)