Word of an upcoming announcement posted recently to the Japanese Okami Twitter account may have sparked wider buzz than anticipated. A new message has been posted clarifying that whatever the announcement entails, it won't be regarding a sequel.
Furthermore, Capcom USA Corporate Officer and Senior Vice President Christian Svensson responded to an inquiry on the Capcom Unity forums by advising fans not to hold their breath on the announcement unless they live in Japan:
Whatever it is, it's likely only in Japan... I've got no details on what they were referring to (but as has been stated, whatever it is, it's not a game).
It’s a bummer to fans waiting for another installment of this beautifully stylized series, for sure. We can only hope that we’ll still see new offerings from the sun goddess in the future.