iPad 3 got confirmed spec as well from the invites. It will features a 9.7-inch screen with 2048×1536 pixel resolution, 264 ppi. Don't be surprise if it equipped with quad core processor (possible A6) as well.
In the invites, Apple suggest "We have something for you to see. And touch". Touch? Could it mean the iconic hardware home button in the new iPad? Since There is possible the next iPad don't have physical home button.
This theory came from Gizmodo
…there seems to be NO home button, which explains the mention of the “And touch.” in their invitation. How can we know? First, the photo they are showing is on portrait mode. You can’t achieve that icon spacing in the landscape mode (which is the only explanation for the lack of home button). Moreover, the icon falls right onto the same water drop that the current iPad 2 falls while in portrait mode. It’s clearly a photo of the iPad in portrait mode. And there’s no button to be seen.
So, they'll have some iconic home button like Android 4.0 in Samsung Galaxy Nexus and fully gesture function like Nokia N9? Stay tune with us next week and you will find the answer.