James Mielke apparently disagrees!

In case people wonder who that is, he worked at Q-Games as a Producer, plus he's held a bunch of different roles within the inustry, he's basically said Sony are going big on new exclusives at E3. Shinobi602 has said the same (very reliable insider), same goes for Verrendus on Neogaf.

Looking at the facts Sony has a lot of 1st party studios, many of which have been incubating projects for many years, particularly the likes of Guerrilla Games, who's new IP has been in development since 2010, SCE Bend's project will be nearly 4 years in the making soon, Media Molecule as well, plus a bunch of others have new IP and then there are the existing franchises that will likely make their return soon.

With Sony selling 3rd party without much effort I very much doubt their attention will be put into this, simply because they don't need to do that.
Even having marketing deals that doesn't mean Sony has to push those games with a lot of stage time at their conference, that's what you pay 3rd parties for. All that's really needed on that front is some short trailers or a montage of those games, maybe with some confirmation from the publisher involved on what's coming to PS4 first.

Shinobi602 has even stated that this talk about Sony's E3 being 3rd party padded has come from nowhere, just fear.
Sony's developers have a lot of games in the works, it's time to show them off!

This fits with Fergal Gara's recent comment on Sony not being concerned about their Fall line-up of exclusives, because they have new titles to announce that are coming out this year, plus they can show footage of games already announced and confirm specific release dates for those games at E3.

What would make the most logical sense as far as 3rd party is concerned is Sony perhaps having some new IPs as exclusives from major publishers.
Kaz Hirai has said about investing in exclusives for PS4 and he wants to solidify PS4's position in the market, which such things would definitely help with.
I only see that happening with some unique stuff that Sony can't necessarily make internally, because their studios are tied up with their own projects.


Overall I think that this E3 should be good for new games from all parties.
The best E3's are the ones where Platform Holders focus on their own, new titles and 3rd party deals with their own stuff.
Some multiplats will always blend into Sony, Microsoft or even Nintendo's event, but with the time being pretty precious at each conference and a lot of new stuff to deal with I doubt any of those events would be 3rd party heavy.