My final predictions are a Healthbook app, TextEdit app, and Preview app as well as an OS X with new icons (much more iOS-like) and a control center. Everything will also be generally more flat.
Google IO is going to be a lot more exciting, with multiple hardware devices and projects announced from Google. However I do look forward to the iOS 8 improvements.
We know those banners went up at the Moscone West center on Friday and there was the Yosemite Park-esque shot behind a big "X" -- apparently this morning there is a mystery banner up, all covered in black.
-Samantha Murphy