The feed has been promoting an unusual fan-page, which is being slowly updated with information regarding previous Ape Escape releases. You can check out the Geocities-esque mid-nineties fan-page through here.
As the page updates with information on the likes of Ape Escape and Ape Escape 2 though, one important Tweet from the Ape Club rings clear - the site will be finished in June 2010, the same month that - of course - E3 happens. Seeing as they're going through the back-catalogue, it makes sense that the final update will include details of Ape Escape PS3 - presumably around the time of Sony's press conference.
Interestingly, the Ape Club page for Piposaru 2001 notes that: "In late 2006, Japan Studio stated that the concept of the upcoming Ape Escape (PS3) game was that it would be a sequel to Piposaru 2001."
Piposaru 2001 never released in Europe or America.