Preview at WWDC likely in June, followed by September launch.
Apple Pushing Back Initial iPad Orders in UK as Shipments to US Customers Begin
Despite our best efforts and those of our shipping partners to get your order to you on time, we want to inform you that it will not arrive on its originally scheduled delivery date.Meanwhile, numerous customers in the United States are reporting that they have received shipment notifications for their iPad orders.
Your new delivery date is 20/03/2012.
Once you receive your Shipment Notification email, you can check the delivery status of your order by clicking the Track Shipment button, or by visiting the Apple Store and clicking Account.
We regret the delay and apologise for the inconvenience.
Apple Online Store
As with previous launches, however, Apple will almost certainly be coordinating with its shipping partners to have the orders delivered on March 16, and shipping information for these customers does indeed reflect this date. It is possible, however, that a handful deliveries may slip through to reach customers a bit early as we have seen in the past.
As for new orders, availability continues to slip model-by-model as Apple runs out of its launch stock for the new device. In the United States, the white 16 GB Wi-Fi iPad has become the first Wi-Fi model to see its date slip, now showing a shipping date of March 19. A number of AT&T 4G LTE models are also listed as shipping on that date.