As good as the Samsung (005930: KS) Galaxy S3’s sales were in its first 100 days from release, things may even get better. According to the Yonhap News Agency, a high-ranking official from Samsung expects that over 30 million Galaxy S3s may be sold by the end of 2012.

Shin Jong-kyun, who heads the IT and Mobile unit of Samsung, offered these predictions to Korean reporters yesterday, just as Apple, Inc. (NASDAQ:AAPL) was unveiling the iPhone 5 over in San Francisco.

Shin was also quite optimistic on the prospects of the Galaxy Note 2, a so-called “phablet” (phone-tablet hybrid) with a 5.5-inch display. He forecasted that about 20 million Galaxy Note 2 units will be sold, or twice the number of first-generation Galaxy Notes sold thus far. This could give Samsung even more leverage in the ongoing sales war versus Apple, whose iPhone 5 is the first to include a 4-inch screen and 4G LTE (Long-Term Evolution) capability.

Also, NPD DisplaySearch forecasted that about 567 million smartphones may be shipped worldwide in 2012; this figure may likely double four years from now. NPD analyst Hiroshi Hayase believes that the iPhone 5 would be a major contributor in driving smartphone growth this year.

According to Hayase, “we can expect smartphone shipments to continue flourishing as users upgrade to the new iPhone.” He added, however, that new smartphone shipments may be lower than originally forecast; this number was once at 220-230 million, but Hayase revised his forecast and now expects 177 million new units to be shipped in 2012 due to market saturation.