You are able to download iOS 6 from the Apple Developer side and there are growing numbers of reports about it. The most interesting part for me: What is new on Safari?
Probably the most important update: <input type= ‘file’/> will be supported from now on! At least you are now able to upload pictures and videos.
Tait Brown published a list of all the updates from the “web development” point of view.
There is also a video about how the iOS 6 Safari will look like for the user including a Buildupload. The Video is from this webpage.
(The picture is from the iOS page on appe.com)