That's what they're saying. From MTV:
MTV News can exclusively confirm that the “Arrested Development” is happening.
“It’s going ahead,” Howard confirmed.
“We’ve been asked to no longer divulge anything or get into the game of who’s in, who’s out,” Howard told us. “People are going to have to see.”
And from E! (thanks, Lindsay):
Inside sources close to the negotiations of the upcoming Arrested Development movie tell me that Superbad and Juno star (and before that, hello, George-Michael Bluth!) Michael Cera has finally agreed to do the feature film project.
It's kind of unfulfilling at this point, isn't it? That's always the danger of stretching a will-they-or-won't-they romance for too long (the romance being between me and an Arrested Development movie). I've been on the edge of "they've got to do it... but maybe they're not, but it seems like they are" for such a long time that I'm numb. At least until I see the first on-set shot of a blue David Cross barely visible in front of a blue screen. Then I'll probably be in giddy country.