The highly anticipated iPad 2 will be available for sale today both online and in stores amidst analysts’ prediction that the new tablet computer will sell over a half a million units in its opening weekend.

Apple began the sale of the iPad 2 online at 1 a.m PST, and will be available in stores at 5 p.m local time today, reports ABC News. Some customers were already braving the rain and lining up to get first dibs at the iPad 2 at the Apple Store on Fifth Avenue in New York, where a man reportedly sold his first spot in line for $800, reports Barron’s for the Wall Street Journal.

Analyst Brian Marshall predicted to Bloomberg that the iPad 2 may sell 600,000 units during its opening weekend and will easily outpace the original iPad. Tim Bajarin of Creative Strategies, Inc. also predicted huge sales for the iPad 2 saying that the iPad line is the fastest-selling technology product in history in terms of revenue. In less than three months, Apple had made $2 billion off the iPad, a number it took six months to reach with the iPhone, he added. He predicts that Apple will sell 500,000 units sold in two days, and says that it has an advantage over the other tablet makers, which are at their first models. Apple also has the advantage of selling the iPad 2 at many of its stores, and additional retail outlets.

“Apple has such a huge lead,” said Bajarin to Bloomberg. “Competitors are going to be chasing Apple for many years.”

Last April, when the first iPad was released, Apple announced that it sold 300,000 in its first day. By the end of the year, the iPad 2 had sold over 15 million units, including 7.3 million during the holiday season, reports ABC News. Many are curious to see whether the new iPad 2, which features several improvements and a sleeker, thinner design, will outdo the first generation iPad.