Analyst Mike Abramsky with RBC Capital Markets told clients — as reported by “AppleInsider” (http://www.appleinsider.com) that of the 15 million iPads sold by Apple in 2010, between 15 and 20% of those early adopters will upgrade to the iPad 2.

He sees up to a fifth of original iPad buyers switching to the iPad 2 over the next 12 months. However, Abramsky says that most who buy an iPad 2 this year will be new to the platform.

He expects Apple will sell 28 million tablets this calendar year. Abramsky forecasts that Apple will sell over 500,000 iPad 2s this weekend.