According to Piper Jaffray Cos. analyst Gene Munster, retail stores run by Apple, Target and Best Buy stated they had run out of stock, with online orders on Apple's website taking up to a month to be delivered.

The half a million sales figure (not officially clarified by Apple), is very high for the follow-up device with arguably few improvements, with the original iPad selling 300 000 units in its first 24 hours.

“iPads are sold out across virtually all channels, we were unable to find any availability,” Munster stated in a research note.

A very interesting point of Munster's research is that his team reported that 70% of the customers they surveyed were first time iPad buyers, not people looking to simply upgrade their old tablet, meaning Apple is still expanding its user base.

Munster predicted that Apple will surpass 5.5 million iPad 2's sold this quarter, a gargantuan number, although it will still take a while for the company to reach the 14.8 million original iPad's sold last year.

Time will tell just how successful the iPad 2 will be as we wait for Apple to release official sales numbers. It must also be noted that (unlike last year), the iPad 2 actually has considerable tablet competition in the market this time around, with Motorola’s Xoom looking like its most powerful contender.