By now, everyone has heard how Microsoft plans to release the next Windows client operating syhstem, Windows 7, in 2010. But what the company is not making clear is what new features the OS will have, a topic that has become fodder for educated speculation.

Analysts said Microsoft probably is keeping tight-lipped about what Windows 7 will look like because at this point, company engineers and executives don't even know.

"They don't want to commit, because they don't have a good idea what's in it," said Michael Silver, an analyst with Gartner. "We're three years out, so you can't really expect that much detail."

Michael Cherry, an analyst with Directions on Microsoft, said with so many people still in the midst of upgrading to the latest client OS, Windows Vista, he's hesitant to speculate on what might be in the next OS. "We barely know the features of the one we just got," he said with a laugh.

That said, Cherry is expecting less "earth-shattering" new features than improvements on some of the new ones found in Windows Vista, such as the Bitlocker encryption feature, which is hard for the average PC user to navigate.

"You have to partition your hard drive and do a bunch of things, and you can only really today protect one drive, whereas many machines have more than one," he said.

Cherry also pointed to a common hardware performance problem many users face because of Vista's "very large footprint." "It's one of the things they might want to address -- hardware utilization and performance," he said. "It's hard to put a big wrapper around that; it just needs to be better."

One Microsoft executive gave a slight hint about what might turn up in Windows 7 earlier this year at the RSA Conference in San Francisco. Ben Fathi, corporate vice president of development with Microsoft's Windows Core Operating System Division, said in an interview that a "fundamental piece of enabling technology," such as a hypervisor or a drastic change in the user interface, would likely turn up in Windows 7.

Fathi also said at RSA in February that Microsoft was in the middle of the planning process for Windows 7's features and would know more over the next few months, which suggests the company now has a good idea what the OS will look like but is declining to disclose that information.

The IDG News Service is a Network World affiliate.