Wi-Fi models of the fourth-generation iPad are now listed as "in stock" at Apple's US and Canadian online stores, checks show. Before its November 2nd launch the hardware switched to a one-week delay, and more recently times were reduced to between 3 and 5 business days. The latest development suggests that Apple has caught up with demand, and that perhaps that public interest is relatively modest, due to the simultaneous introduction of the Mini and very few differences with the third-generation iPad, which was only released in March.