But software would need to be written to support the 64-bit ARM instruction set, and porting many x86 64-bit applications is a challenge, King said. Existing applications that ran on previous versions of Windows do not run on RT.

"From a purely technical perspective, porting many common x86 applications to ARM is problematic," King said.

There are also questions on how developers will take the move from 32-bit to 64-bit, King said. But if customers want applications, the developers will deliver.

"These are some of the obvious challenges. Fortunately, everyone involved has a year or more to sort things out," King said.