Looks like the official launch is set on March 6th.
Sigma's announcement in English is here.
Just click "02.20" (today's date) on the right hand side (titled "information") of the page.
On the left hand side (titled "what's new"), they also announce the launch schedule for accesaries and prices before tax.
I cannot but smiling when I read the title of the announcement - to "those who waited patiently for SD 14". Yeah, they postponed it twice. - and lost the Christmas sales season.