So it would be quite strange to see Nintendo move away from Samus Aran and put players in the shoes of a space pirate, but since nothing is clear at the moment, these are just wild guesses. The whole banner could mean nothing more but a new manga entry and not a brand new game – we’ll never know until Nitnendo decides to offer a bit more details (preferably in English). We’re waiting, we have all the time in the world.
Update: Apparently, the text in Japanese below the English announcement reads “Follow Metroid Prime’s history from the perspective of the Space Pirates” (according to Cubed3). This means that we will indeed wave Samus Aran goodbye (at least as a playable character) if there’s an upcoming game coming. Too many “ifs” here…