Even more people will be annoying you with their iPad superiority in 2010 than we'd previously thought. And in 2011 it'll outsell Macs, unit for unit. So says a prominent industry analyst [2]. He's probably right, and it bodes well for Apple's shareholders (as well as changing the entire PC business).

Previously Piper Jaffray analyst Gene Munster had thought somewhere around 14 million iPads would be sold by Apple this year, but in a new briefing today he's upped this forecast by about 50% to a figure of 21 million. That's a big difference--is this an embarrassing turn-around for an analyst who should've known better in the first place, or a tribute to Apple's staged plan for iPad success? It's a bit of both.

Munster's new thinking is based on three changes in the iPad sales process: Increased supply and better distribution systems are pushing more units into the sales funnel, the device is going on sale in more markets around the world, and there's been a surge in buying for the business PC sector. Munster doesn't mention the self-perpetuating success-breeds-success effect, but we think that's also playing a role here--as the iPad receives critical and popular acclaim in the countries it's already available in, it will be pushing up demand and excitement overseas. He does suggest that broader distribution in U.S. stores is helping matters, but again the iPad is an international phenomenon, and in some of its foreign markets it's already available through numerous venues in the same nation.

China is a new market for the iPad, and that'll inevitably push up sales even though it's comparative price there is significantly higher than in the U.S. or Europe, simply because the Chinese market is so vast that many units will sell to those who can afford them.

But its his predictions for the iPad's future in developing nations that are going to be most interesting to industry observers--the iPad is the "Mac for the masses" due to its relatively high power, portability and long battery life. Its price bracket is far above netbooks, Nick Negroponte's XO PC, and India's fabled (and now besmirched) "$35 tablet" but it is just powerful enough, and more affordable in some ways than bigger full-power PCs. Based on this thinking, and the impressive uptake by enterprise buyers, PJ has increased its prediction for Apple's 2011 revenues up to $83.13 billion from $78.96 billion.

It's easy to dismiss the reports of analysts like Munster as so much noise from people who are only tangentially connected to the industry, but in this case it's the change in Munster's mind that's important. The 50% bump in his prediction is a figure that's big enough to make execs in Dell, HTC, RIM, and all the other tablet PC companies to sit up and adjust their strategies.

To keep up with this news, follow me, Kit Eaton [3], on Twitter.