Microsoft on Tuesday revealed that it will offer an Office 2010 Technology Guarantee Program by the end of March. Under terms of the program, users who purchase various Office 2007 versions will receive a free copy of the equivalent version of Office 2010.

Buyers of Microsoft's best-selling version of the suite, Office Home and Student 2007, will receive a free copy of Office Home and Student 2010, according to the company. Those who purchase Office Standard 2007 will also get a free copy of Office Home and Business 2010, a new product edition in this generation. Those who purchase Office Small Business 2007 or Office Professional 2007 will get a free copy of Office Professional 2010.

Although the company didn't confirm the exact timing of the program, a previously leaked document suggested that it would begin March 5 and end September 30. (And Microsoft CFO Peter Klein did say that it would come early in the month.) Microsoft is expected to finalize the code for Office 2010 soon, and my sources tell me that general availability of the suite is expected June 15, 2010.