Neo-Era wrote:Gundam SEED was formally announced in July 2002 and began airing the following October. SEED Destiny, which first aired in October 2004, was also officially announced in July of the year it came out, central cast and Impulse Gundam included.
So I'm guessing we'll see the official unveiling of the 00 Gundam by early July.
This also holds true for the first season of Gundam 00. We saw the series officially announced with Gundam00.net and all in July, and the series (obviously) followed suit in October. So we'll definitely see Gundam 00 S2 info in a few months. I think we'll likely see the main cast revealed (and the official fates of the old cast), along with the main Gundams to show up in the series. We'll probably also see significant announcements for Gunpla, such as a MG Exia.
There's no doubt that Sunrise/Bandai will make sure this series gets a good head start with the hype before it starts to air. And, like Neo-Era points out, they are generally doing so about two months in advance. I don't see them keeping S2 very secret when it comes to characters and mecha (however, plot is another matter).