If I had to pick one, it would have to be the PS4 at this point.
The reports coming out about the XBOX One are confusing and make it sound like they will make it harder for you to sell games when you have completed them, and the statement that an internet connection is required - but not all of the time.
I'm not sure whether I have any interest in the social features of the PS4 though, so I would hope that it an option that can be disabled if wanted. There's also the fact that we don't even know what the PS4 console itself looks like yet!
To be honest, I don't know if I'll buy either console at all as I'm not sure I'd even use them much. If I did decide to though, it probably wouldn't be at launch.
Also, with the name being XBOX One, I doubt it will be long before some people try to scam others by selling original XBOX consoles. I guess that's only to be expected though, like the ones who will try to scam by selling JUST the cardboard box of the console (as many have done in the past with previous ones).