It's NOT in landscape mode.
I've just attempted to recreate this shot using my iPad 2 and the bubble cluster (or rain drops, whatever you like..) just above the finger is only visible in portrait mode.
Also, the 3 icons are on the far right edge of the dock (again, identified by the bubble cluster), so this doesn't suggest at all that there's no home button because the shot can be taken without including the home button.
The photo is a mockup, I believe, becuase I just couldn't get the angles right to show the same proportion of icons, bubbles, finger or bezel.