The most important point: to have your iPad be made available for launch you need to submit it by March 27th. The App review team will e-mail you with submission feedback about the readiness of your application for App Store distribution. You will also receive information about submitting your apps for final review, before the iPad ships.
Full email below:
iPad will begin shipping soon and your opportunity to be part of the grand opening of the iPad App Store starts today. Submit your iPad app now for an initial review by the App Review Team and receive feedback on its readiness for the grand opening.
Submit Your App by March 27.
– Build and test your iPad app using iPhone SDK 3.2 beta 5 available on the iPhone Dev Center. Only iPad apps built with iPhone SDK 3.2 beta 5 will be accepted for this initial review.
– Upload your distribution signed app through iTunes Connect by Saturday, March 27, 5pm PDT.
– The App Review Team will review your app on iPad and email you details about the readiness of your app.
– You will also receive additional information about submitting your app for final review before iPad ships.
– Only apps submitted for the initial review will be considered for the grand opening of the iPad App Store.