As Microsoft prepares to detail new features coming to Windows 10 at a January press event, pre-consumer builds have already given us some glimpses at the next-gen OS. The latest, build 9901, includes a more refined design for Cortana and a number of other tweaks and new apps.

Microsoft's answer to Siri and Google Now first appeared in a video demo earlier this month, but that particular build had a pretty barebones UI. The most recent implementation looks far more polished and is likely much closer to what it will look like in Windows 10. Namely, Cortana sits at the top of the search interface for Windows 10, which itself has a new home in the task bar.

Microsoft's assistant will respond to text and voice commands and overall it works very similar to the Windows Phone version, with the ability to summon it with the words "Hey Cortana". Needless to say it's not 100% functional yet.

There are several new and updated Modern UI apps such as Camera, Calculator, Alarms, Remind Me, Photos, Contact Support and a Getting Started app. Also in build 9901 is a new Xbox app that appears to work as a central hub for achievements, friends lists, activity feeds, and the Store.

Paul Thurrott has a detailed changelog of the new build over at WinSupersite, while the video above from WinBeta shows some of the new features in action.