After checking out the Apple iPad 2’s opening-day sales scenario with several Apple retail stores around the US, Piper Jaffray analyst Gene Munster has made an upward revision of first day sales estimate for the device to 500,000 units. Munster had said in an earlier-this-week research note that the over 10,000 stores of retail partners will witness comparatively much shorter first-day queues for the iPad 2 vis-à-vis those for the original iPad which was released last year.

However, Munster has now increased its launch-day sales projections for the iPad 2, as the initial demand for the device has already surpassed his expectations - with some Apple retail stores drawing 104 percent longer first-day sales lines than those for the original iPad.

Munster checks with the stores have revealed that the launch-day queues for the iPad 2 were notably more impressive than the lines witnessed last year for the original iPad at some stores – including the Mall of America Apple Store in Minneapolis, and even Apple's flagship 5th Avenue store in New York as well as Apple Store in downtown San Francisco.

As per Munster, the overwhelming demand for the iPad 2 so quickly outstripped initial supply that some stores had "spotty supply" barely within an hour of the device’s launch. Nonetheless, Munster also opined that Apple "felt it was well stocked" for the launch; more so as there has been in “"dramatic increase in distribution points.”