Analyst estimates 700,000 iPads sold Saturday
A Piper Jaffray analyst revises sales estimates upward--more than doubling his previous estimate of how many tablets Apple would sell the first day.

If early sales estimates are any indicator, Apple appears to have another hit on its hands with the iPad.
Including presales, Apple sold 600,000 to 700,000 of the new tablet on Saturday, according to estimates released by Piper Jaffray senior analyst Gene Munster. That is more than double his earlier prediction of 200,000 to 300,000 first-day sales. At least 730 people lined up Saturday at Apple's flagship Fifth Avenue store in New York City--more than the number who showed up for the iPhone or iPhone 3GS launches, he said.
By comparison, Apple sold around a half-million iPhones the first weekend it was available for purchase in 2007, according to Munster's estimates at the time.
Munster's team polled 20 Apple stores around the nation on Saturday night and found that 19 still had tablets on hand. Twitter users reported mixed availability at Best Buy stores, the only retailer other than Apple that was supposed to have iPads in stock.
Presales went so well that Apple updated its Web site last week to push back shipping on new orders to April 12. Some sources say Apple sold hundreds of thousands iPads since it began taking preorders on March 12.
Apple could sell up to 7.1 million iPads worldwide this year, according to a preliminary forecast released Friday by iSuppli. Sales will double to 14.4 million units next year and triple to 20.1 million in 2012, the research firm predicts.