However well iPad 2 does over the course of 2011, a loss of market share for Apple is inevitable, if only because of the number of competitors due to hit the market.

Early estimates from the tablet's launch weekend in the US, however, may give the likes of Motorola, HP, RIM and Samsung that sinking feeling.

Taking stock

The most conservative estimate so far comes from Piper Jaffray's Gene Munster, who believes somewhere in the region of 400,000 to 500,000 units may have been in consumers' hands by the start of Monday.

Having both checked with retailers for stock and conducted a survey of those waiting in the queues to buy an iPad 2, Munster believes the majority of those half a million were sold on day one, with shops failing to receive any new stock over the course of the rest of the weekend.

Reuters, however, cite a number of analysts who believe iPad 2's sales tally edged far closer to the 1 million mark.

To put that estimate in some kind of context, it took the original iPad 28 days to surpass sales of 1 million, with initial launch sales coming in at around 300,000 units.

Apple amazed

"Our field checks over the weekend indicate that the iPad 2 sold out at every Apple and non-Apple store we contacted," Ticonderoga Securities analyst Brian White said in a note, backing up Munster's take on the stock situation.

"In fact, all the stores had worked through iPad 2 inventory by Saturday afternoon, and there were no new iPad 2 deliveries on Sunday."

Official figures are a mystery, although Apple spokesperson Trudy Muller is quoted as describing as launch demand as "amazing".

"We are working hard to get iPad 2 into the hands of every customer who wants one as quickly as possible."