Apple has just sent out invitations for an Apple event at the Yerba Buena Center for the Arts in San Francisco at 10am PST (5am AEDT) on Wednesday, March 7. On the invitation, you can clearly see its new Retina display in all its glory.
Compare the top (invitation) to the bottom (a photo of iPad 2). The top has a lot more definition. It's clear on the typography in the Wednesday and the edges of the icon.
Not only that, but there seems to be NO home button, which explains the mention of the "And touch". in their invitation. How do we know. First, the photo they are showing is on portrait mode. You can't achieve that icon spacing in the landscape mode. Moreover, the icon falls right onto the same water drop that the current iPad 2 falls while in portrait mode. It's a photo in portrait mode. And there's no button to be seen.