I don't know if any of this has been said already but I don't want to read through 33 pages of comments, but heres my opinion on the matter.
Retina iPad? The product is definitely an iPad. The screen appears to be a retina display, though with the resolution it is hard to be sure, but it definitely looks crisp. When photographing a screen, the image usually appears even more pixilated, but here it seems to remain crisp.
Icons? I think that the icons were vary carefully chosen and have meaning and here are my ideas.
a. keynote. The obvious reason they included this is because this is going to be a keynote presentation as every new product announcement is. However, I think there might be reason beyond that. It could be that they wanted to remind the public of their iPad office apps do to the possible imminent release of Microsoft office.
b. calendar. Apple has used this before, and it seems to just be an indication of the event date which is what everyone cares about most, s it is prominent.
c. This icon I find the most mysterious. It could simply be indicating where it is. The map shows Cupertino, which is near the San Francisco center where they will be having the event, but they are not the same. They used it on the iPhone 4S invitation to indicate their headquarters so I don't see them using it to indicate elsewhere. It does seem to hint at the release of a new mapping app which has been in the works for years, but then its odd they would use the icon for their competitor's(google) app to suggest this. This could be reading way too much into it, and it could just be indicating its in california and not new york as other rumors were indicating, though Apple does put alot of thought into these things...
No Home Button? The main argument for there still being a home button is that the iPad could be in landscape position, but it can't, and here is why:
a. the icons in landscape view even when you have the maximum of 6 are not as close together as the icons in the image.
b. the spacing of the icons is exactly the same as having 5 icons on the bar when in portrait view.
c. the wallpaper is the standard wallpaper for the iPad, and I don't think they would tweak it just for this, just when in landscape mode, it crops the image and the specific droplets do not appear on the screen where they do in the image, where as in portrait view they appear exactly where they are shown.
So the iPad is in face in portrait position with 5 icons in the bar, but there is no home button, so there are three possibilities:
a. The iPad is upside down. The problem with this theory is that the camera would be visible. So either it isn't showing through the screen or they removed it from this device as some people have suggested which I find extremely unlikely because this is intended as a FaceTime device and they wouldn't remove a feature. Also, I don't think Apple would promote their device upside-down.
Edit: I just checked and it also appears that if it were upside-down the camera might be cropped out of the photo by about a millimeter, so it could just be upside-down.
b. The photograph didn't capture it. I tried to replicate the photo and found the button was not visible in the camera because of the exposure because of the brightness of the screen in relation, if you notice the bottom of the page appears darker just below the text so they could have darkened it out unintentionally. Though this seems unlikely
c. They have removed the home button to allow for exclusively multitouch gestures instead. I wouldn't miss this because I often accidentally hit the home button on my iPad when using it in portrait views and the home buttons have a tendency to break. However the leaked iPad screen suggests otherwise.
See. And Touch? I have been trying to decode the phrasing at the bottom, and I haven't reached any conclusions, but I have two contrasting ideas.
First, Their use of the word something seems to suggest one thing and one product launch which would suggest the iPad obviously, but this seems unlikely.
What is more compelling the the "And touch." as a second sentence. Had they said, "We have something you really have to see and touch." that would suggest you should see their new iPad and touch it because it has a touch screen, but the pause suggests there are two things: We have something for you to see. And we have something for you to touch. This tells me they are announcing the new iPad and "something you really have to see." New Apple TV? This is my best guess. I doubt they have their iTV ready though.
Don't expect too many people to have read all of this, but, thoughts?