I seem to remember Sony announcing it in their official conference at GDC in 2007.  That seems to me to be in March of 2007.  If that's not too far before December 2008, I don't know what is. 

Whether or not it was leaked before then is another matter, but Sony made the decision to go public 21 months before release.  When (if) Nintendo announces Kid Icarus, we won't be all 'meh' because IGN has been touting it for a year now; we'll be excited to finally see the fruits of their labor.  Sony could have withheld Home, they chose not to.

I think you mean last year But you're right, they've released plenty of things on time.

I don't think anyone was really that excited about playing Second Life on Playstation 3 anyway

You cant with with fanboys,any logical gamer knows you can announce something 2 years before its released,cause all the hype will die out like TW.

A-duh.

Kotaku, and Brian Crecente in particular, outed Home a week before GDC 07, even after Sony contacted them and explicitly asked them not to. Sony was pissed and blackballed Kotaku from then. It took a while for them to kiss and make up (and explains the animosity Kotaku has for the black box)

The point is, Sony had little choice but to spill all the beans after this.

Or, they could have waited to announce it at a later date.  Kotaku would have been left without verification of their claims, eventually people would have forgotten about it.  They chose to hype it, and frankly, the timing is such that I wonder if they were going to announce it anyways.

Like I said; they didn't have to announce it formally.  Nintendo hasn't formally announced anything about Kid Icarus (if it exists), and IGN's been harping on that forever.  Just the other day, someone posted about a Sega employee leaking Sonic Unleashed waaay before initial announcement; this kind of thing happens.  If they wanted to keep it a secret, they could have.  They just saw the reaction to Kotaku's piece, and decided that there was the ability to get a lot of publicity (if they weren't planning on talking about it anyway).  They got greedy and took the short-term publicity over the long-term hype.  Don't blame Kotaku; Sony chose to give the conference.

Isn't that what Sony does best, hype stuff too early. I know they don't do it with everything but the big guns are hyped years before release.

KZ2?

Only Sony is to blame if they can't keep their projects secret unless there was a signed NDA.