"What does this mean for HealthVault? The 'buzz' online ranges wildly, but the real and simple answer is: nothing," Sean Nolan, chief architect for Microsoft's Health Solutions Group, Sunday.

He pointed to some advancements to show Microsoft's commitment to the service. It recently made HealthVault accessible from and released a software development kit for third parties to develop mobile applications for the service.

It also started to let users such as X-rays and scans to their files, and it now lets from government health systems.

But some observers wondered if Microsoft will continue that pace of innovation after losing a big competitor. and could decide to reassign engineers to other projects, John Moore, an analyst at Chilmark Research, wrote in a blog post. "It's not like HealthVault has been a screaming success in the market," he wrote.

Microsoft didn't respond to a question Monday afternoon about how many active users HealthVault has.