Windows testers will get a new beta version of Windows Vista, dubbed the December Community Technology Preview beta build, just before next week's holidays, according to tester scuttlebutt.

New to the December release, testers say, will be a number of features and user-interface tweaks. A new defrag module; tight integration of Windows Defender (the product formerly known as Windows Antispyware); and a functional parental-controls filter are all rumored to be in the December Vista build.

OEMs and independent software vendor (ISV) partners are expected to get the December CTP any day now. And Microsoft Developer Network (MSDN) and other Vista testers will be able to get their hands on the build by Monday or Tuesday, if Microsoft sticks to its plans, the testers claim.

While it's uncertain exactly which Vista build Microsoft will christen the December CTP, most testers are expecting it to be 5270. While some testers claim to have seen Vista build 5276, it sounds like 5270 is more likely to get official approval for external testing.

This week, Vista build number confusion hit some testers. Some testers said they thought the Vista build that included was the December MSDN deliverables was the December Vista CTP. In fact, however, it was actually the October CTP build, a k a Vista build 5231.

As reported last month, Microsoft did not release a Vista November CTP. Instead, the company opted to label build 5259 as an Integrated Developer Workstation build, claiming it was not of CTP quality.

(CTPs are interim pre-release versions of a Microsoft product that are not beta quality. They represent a snapshot of a product under development at a given time, and are meant for developers and testers who aren't afraid to be on the bleeding edge.)

The user interface in the expected December CTP (build 5270) looks somewhat similar to the UI in previous builds, "except that the Display properties have been replaced by some sort of activity center called 'Personalize Windows' (also seen in Build 5259)," said one tester contacted by Microsoft Watch last month.

Another tester said to expect "some aesthetical changes to Vista's UI. He said users "will be able to customize the color of the Vista glass in all colors of the spectrum."

It sounds like the expected Tablet PC feature integration will likely be part of the December CTP, as well, based on some recent Microsoft blogger posts.

"I'm really looking forward to hearing what you think of TabletPC features in Windows Vista when you see this new CTP," blogged Microsoft test engineer Hilton Locke. "We've come a lo-o-ong way from the Beta1 or even the September CTP."

Microsoft has been expected to fold much of its Tablet PC functionality into Vista, and specifically, the Windows Presentation Foundation subsystem, for some time now.

One of the aforementioned Vista testers also said to expect some Vista firewall changes some time in the next few builds.

"Right now, a lot of (Microsoft) staffers are talking about making changes to the firewall I'm not sure if we'll see any of those changes in the December CTP, though," he said.

Among the firewall-related change in the works, according to the tipster: