It's hard to believe, but Apple's online store shipment estimates for the iPad 2 are already at 2-3 weeks. The new device only went on sale today at 1:00 am PT, but already it seems that supply is going to be limited over the next few weeks at least.
If you're desperate to get your hands on an iPad 2 today (and you live in the U.S.), your best bet is to head out to your nearest Apple retail store and start queuing, if you haven't done so already. The iPad 2 will be on sale at Apple's retail stores at 5:00 pm local time.
The tablet is due for international release on the 25th of March.