According to the Guardian, his Summer’s pavillion will be designed by:

Sanaa, a Tokyo practice founded by Kazuyo Sejima (48) and Ryue Nishizawa (38) in 1995.

Like Ito, Sanaa’s work is ethereal, exquisite, translucent and testing. Very quietly, very gently, Sejima and Nishizawa, have pushed the boundaries of contemporary architecture. It might be a little corny to say they have done so in a Zen-like fashion, and yet their buildings, interiors, installations, furniture and other designs have been remarkably calm and quieting, objects for contemplation as well as buildings and designs with a practical purpose.

Quite what Sanaa will do for the Serpentine and Kensington Gardens remains to be seen, but if their best known building to date, The New Museum of Contemporary Art, New York, completed four years ago, is anything to go by, it will be sculptural, peaceful and gently haunting.

Serpentine Turns to Japanese Architects for 2009 Pavillion (Guardian)