Having a stacked holiday is not always detrimental to the games' individual success. I thought that last year with so many big games, that some would flop. Surprisingly, a great deal of games went on to be the best selling in their franchise (Gears, Uncharted, Call of Duty, Skyrim, Batman, Battlefield, etc.)

No DMC yet? Me sad
But I don´t believe the dates anyway

Sony is just trying to attack Wii U (as Microsoft) and hold 360's advantage in year's end (Kinect probably won't sell consoles like it did last year). If it works, Sony could really outsell the competition by a good margin this year as they have the sales advantage most time of the year.

If Sony do really go for a spring release do you think they'll announce Orbis at TGS? I've been wondering when they could announce it, because this E3 would be too early and next E3 would be too late.

The december releases seem a bit weird. Probably just place holders of some sort.

Last of Us and Playstation All-Stars Battle Royale will surely be significant titles for the PS3 but the dates seem too close to Christmas and we may see them miss out on the Christmas rush. I predict very early 2013 for Last of Us and late November for Playstation All-Stars Battle Royale.

E3 would not be to early in any way if they are launching spring 2013. That's less then a years notice and Sony has in the past given ample notice for its next consoles. Fact is several developers have stated with or without the console manufacturers unveiling the next generation games will be at E3. It would not make sense for all the games to be shown at E3 with no hardware announced. Actually considering many E3 games come out within the next year all these next generation titles indicate next generation machines are coming soon. In fact I am still skeptical that NextBox won't be present. PS4 I am 70% certain will be announced if not unveiled we will hear something I am almost certain. A TGS full unveil wouldn't be surprising either. Sony needs to dominate in Japan and unveiling it closer to WiiU's launch date would give Sony some time to incorporate Nintendo technology into PS4 hardware. TGS would be a great venue to show off the PS4. However if Sony doesn't show something at E3 and Microsoft isn't full of shit meaning neither do they. Then Nintendo will dominate E3 without even the slightest challenge! I really doubt Microsoft or Sony want to be entirely over shadowed at E3.

Not happening. I cant remember last time big game was released in december.
Ratchet coll. is "irrelevant in sony plans", its just there as fan favour(maybe to make some new) and profit. Long/short story not big release.
Lbp karting is listed for september on many EU retailers which make sense.( not that much competition aside from hitman, borderlands, far cry)
October is worst month this year( bioshock, re6, ac3, maybe dishonored if its big hit, tomb raider, fifa, new medal of honor...). If i was sony i d put all stars game here if not later, early 2013.
Last of us should be left in november, as far i know its "only" cod month, not other big releases. It can be good move for sales( like ac rev.) March of 2013 is for gow a.
There ll be new announcements at e3 but i doubt those ll be released this holiday.

sony dont want last of us to get caught in middle of halo and call of duty so make sense to release in december

I go to Video Games Plus, those dates aren't concrete. Though they try their best to find the right dates.