It's gonna be the PS4. They're going to get the jump on Microsoft by announcing the PS4 before Microsoft is most likely decide to announce fully the release date of their Xbox 720. The PS4 will most likely be released to the market early 2014, the Sony employee's are trying to push the deadline to before Christmas 2013 because the rumor is Microsoft is going to announce the Xbox 720's release date at E3 and it's going to be before Christmas, this will give them a pretty big edge.
Also, with rumors of specs flying everywhere it looks like we're going to be in for a treat.
8 GB system memory - This looks like it's going to be a big possibility, Microsoft have already leaked the Xbox 720 will have 8 GB's so Sony had to step up their game because their original idea was 4 GB's.
8 Cores - Pretty much around what the Xbox 720 is leaking.
Leaked GPU - AMD R10xx
Can't remember the rest, I'll try to find it again in my spare time.
Just a side note about the Xbox 720
They say it's going to have a Blu-Ray disk drive, which seems weird since Blu-Ray is a product which Sony will make money off, meaning for each Xbox 720 sold Microsoft with be giving money to their big competitors.
And a side note about both.
Both seem to be going in the same direction of not allowing used games. I don't know how I feel about that, if they go the same way as steam and make a lot of deals, then it should be fine.