UPDATED: Sigma 24-105mm F/4 OS Art Lens Confirmed
UPDATED: Estimated arrival date released. In a stunning development, Sigma has placed the rumored 24-105mm on their website. I say stunning, because the whole of the Sigma USA team is on holiday today and we were never briefed on this lens officially (which is HIGHLY unusual, eg. this is the first time it's happened). This story is still developing, but the page is live and you can look at it yourself.