I see no reason getting a ps4 early since most of the game that will be released on ps4 will also be on ps3, at least until next summer...
I see new games released only on ps4 been delivery around spring 2014, this is where I'll start considering buying the new console, not before.
There's a lot of things that can happen unitl next year, so I'll see what's up in the meantime.
Havn`t fully decided yet, I was thinking around release date, but I would like to finish up my PS3 games first, which as far as I know all the PS3 games I will be buying are out this year. The ones on both PS3 and PS4 I will just buy the PS4 version, even if I don`t have the system yet. I will definitely have the PS4 within a year of it`s release. I just can`t tell an exact date, as even if I did buy it at launch I would want to finish up my PS3 games first anyway before I would start the PS4, so I think it would be best to just wait until I am down to my last game for PS3. It could be still around launch, all depends how long it takes me to finish them as they are not all out at one time, so I will be playing them all through the year.