I'm still seeing the beta tab icon for the Main site...
(I see the new design on the Meta site)
See this post-launch post. You'll need to do a hard refresh (F5) of the page, or manually refresh the favicons, as described in the post.
I'm still seeing the Beta apple-touch-icon.png as well. But I confirmed the image file I checked in is the new one. After talking to our dev, he said it's cached on the server side by our CDN. A lot people are seeing the new one already. I think it's just matter of time when the new icon propagates completely.