"We're working very hard on the next version of Windows Mobile," said Peter Klein, Microsoft's chief financial officer.
"We'll be talking more about that in Barcelona in a few weeks."
General Manager of Investor Relations for Microsoft Bill Koefoed also made a reference to Windows Mobile.
"We also continue to make progress in the mobile space, and you will hear more about that at Mobile World Congress in February," Koefoed said.
The statements by Klein and Koefoed reiterate statements made by Microsoft CEO Steve Ballmer that the company would make a Windows Mobile announcement in Barcelona. But it's not clear yet what Microsoft will unveil.
Many expect Microsoft to discuss Windows Mobile 7 - the next major upgrade for Microsoft's mobile OS. But Microsoft has cast some doubt on that assertion in recent weeks.
Earlier this month, Beta News posted an interview with Windows Phone Senior Marketing Manager Greg Sullivan discussing what Beta News believed to be a preview of WM7.
However, Beta News later reported that Microsoft contacted the blog and said Sullivan's comments were not specifically about WM7. This led Beta News to believe Microsoft will not be discussing WM7 next month in Barcelona.
If that's the case, then Microsoft may be announcing a rumored Windows Mobile 6.6, which is said to be an incremental upgrade from Windows Mobile 6.5.
Another popular prediction says Microsoft will announce its oft-rumored Zune Phone in Barcelona.
Current rumors suggest there may be two versions of WM7 - a business and a media edition - and the new OS may include some kind of integration with Xbox LIVE.
Windows Mobile 7 was expected to launch this year, but some rumors suggest the Mobile OS may be delayed until 2011.
When asked to clarify whether Microsoft intends to announce Windows Mobile 7 next month in Barcelona, a Microsoft spokesperson said: "we're always working on future versions and have nothing new to announce".
See also: Windows Mobile 7: When, where, what?