Just wondering how long it typically takes to be able to actually purchase a product once Apple announces updates? I know the MBP are due for an update anytime now, but if they announced updates tomorrow, when do they typically have the updated computers for sale? Is there a time lag between the announcement and when you can purchase them? The iPad was announced in January but won't be available until April. I realize this is a new product which is why there is such a delay, but is it usually a couple of weeks before you can get updated Apple products? A month? Right away? Thanks.