We released results on the first detection of CMB polarization at the COSMO-02 conference on Thursday 19 Sept 2002. Streaming video of the talk is available here.
Local pdf files: Instrument Paper, Results Paper
Nature's website: Instrument Paper, Results Paper, Zaldarriaga review article
Announcement talks in pdf: Main talk - Press conference
Press Release, Print quality images (From press release page)
An earlier DASI polarization talk (with some technical detail)