The official notice has gone up, and I am now free to reveal that the first set of Planck Cosmological results will be announced on 21st March.
The word from the official CNES web pages is:
Presentation of the first cosmologic results of Planck mission as well as its first all-sky images of the Cosmic Microwave Background
Launched in 2009, Planck studies the Cosmic Microwave Background – the relic radiation from the Big Bang – to allow cosmologists to zero-in on theories that describe the Universe’s birth and evolution. The first all-sky images of the Cosmic Microwave Background will be presented at the press conference held in Paris ESA HQ on March 21st, 2013.
As well as the press conference in Paris, we’re hoping that we can arrange some events in the UK as well, which will be convenient for me as I’m lecturing that morning and so will be unable to escape to Paris.