New Microsoft Surface Pro 2 tablets at a Microsoft store in the Dadeland Mall on October 22, 2013 in Miami, Florida.  - 

Microsoft CEO Satya Nadella on Thursday is scheduled to hold his first major press event where he is expected announce a version of Microsoft Office for the Apple iPad. That's something Microsoft has resisted for a long time.

"We think [not developing Office for iPad] was a mistake," says Forrester Research’s Frank Gillet. He says Microsoft’s stubbornness has cost the company more than a billion dollars in revenue because the iPad is the most popular tablet on the market.

According to David Cearley, an analyst with Gartner Research, Office for iPad could signify something important about Microsoft’s future, a willingness to look beyond the company's "insular" environment.

Microsoft had worried that making Microsoft Office products available on iPad would undermine the company's own Surface tablet device.

Follow David Gura at @davidgura