I'm not sure if this is actually proof that the release date is in fact the 24th, but having used Bill Me Later for my iPad 3G, I've been checking the account nearly every day and until today, the purchase was listed under pending transactions (since it hasn't shipped/charged yet). Today, it is still not listed under the normal transactions section of my account, but it is no longer under pending transactions (I'm assuming it is somewhere in between, whatever that means; still says I made the purchase, but it isn't in either section any more). So, whether it is proof or not, I'd thought I'd share it in case it sheds any light on the matter.