One analyst’s note to investors today predicts big things for Apple’s iPhone this year -- even without the device expanding its distribution to other carriers such as the rumored Verizon deal.

Overall, Piper Jaffray’s Gene Munster predicts that Apple will sell 36 million iPhones worldwide in 2010, a 40% increase from last year’s estimates, according to AppleInsider. But they also concede that those numbers are “conservative” and don’t include the possibility of Apple expanding to other carriers on its home turf.

“We estimate unit figures for the U.S., U.K., France and Germany, then divided the remaining units proportionally by sub count among the remaining carriers,” Munster explains. “The results show that our international iPhone estimates may be a point of conservatism in our model.”

Munster anticipates that AT&T alone will move 15.8 million iPhones this year to its subscriber base of 82.5 million. The note to investors also speculates that the new year will bring two new carriers in France, Canada and the U.K., the first full year of sales in China, and that sales will be driven by a new iPhone model expected to arrive mid-year.

For now, AT&T is the exclusive carrier of the iPhone here in the U.S., but Munster and others have previously predicted that Verizon will be the next coup for Apple’s handset. With AT&T’s exclusivity agreement rumored to end this year, recent reports say a Verizon-capable iPhone could arrive this year, despite rumors that Apple and Verizon are having a pricing spat regarding a CDMA-based iPhone.

“We continue to believe that it is highly likely that Verizon will launch the iPhone by the end of 2010,” Munster said. “However, Verizon is not in our model and may be a source of significant upside for iPhone units in 2010 and beyond.”

Even without a Verizon iPhone, Munster goes even further to forecast 21.3 million device sales in the U.S. alone by 2011, with at least 48.5 million total unit sales worldwide next year.