Maaya Sakamoto will be the narrator for the Festival's original animation. No word on an appearance yet. It was announced earlier that Nana Mizuki and Hiroshi Kamiya will voice the new characters of Anzu Nekota and Naomasa Goushi.
Other events have been added to their website:
Sakura Tange and Junko Iwao will sing a duet.
There will be a Cardcaptor Sakura Festival featuring a medley of five songs.
There will be a CLAMP Cafe with Mokona-yaki & Mokona-no-monaka for sale.
CLAMP will provide the cover illustration to the Official Guide Book.
There will be some cosplay event, new CLAMP merchandise for sale...and more.