Heads up! We've gotten a ton of tips from our friends across the pond and down under that Apple's now sending shipment notifications for those who pre-ordered the iPad -- both the 3G and WiFi-only models, from what we've seen -- about one week before that famed May 28 international launch date. Now, before you start thinking you need to take off work a few days earlier, don't forget that those in the US also got notifications a week before release and still no one got an early present. In