Almost every exclusive game of the holidays 2012 (or even earlier) was first announced this year.

[F0X]

A few were revealed in previous years. Paper Mario: Sticker Star was one of the first 3DS games to be announced, and Persona 4 Golden was revealed in August of last year. Halo 4 was revealed at E3 2011. I know you aren't counting Wii U, but NSMBU was basically shown in an early form at E3 2011 as well. As for Sony... yeah, all their first-party holiday games were unknown quanities before this year, which I believe is your point. I personally expect most major holiday titles for 2013 to be announced by the time E3 2013 rolls around.