Within the next 24 hours, Microsoft will finally issue a major set of updates for the core “Metro” apps in Windows 8 and RT, in this case the communications apps. Here’s what’s changing in the People app.

Note: I received a sneak peek of these changes late last week. However, I do not have the new app versions yet, and won’t until they’re publically released before early morning (Pacific Time) on Tuesday. (They could come as early as Monday night.)

This represents the third major “version” of the communications apps provided in Windows 8. The first version, of course, ships with Windows 8/RT as part of the core OS image. The second version was provided right before the general availability of Windows 8 and is installed alongside a ton of other app updates after you’ve booted into the system for the first time. You can read about the changes in that second update in Windows 8 App Update: Mail, Calendar, People and Messaging.

Here’s what’s new in the People app.

New app bar. The People app now sports a new top-mounted app bar modeled after that in the Bing apps which the main functional areas of the app—Home, Me, and What’s New—can be reached more easily. (The bottom app bar is still present as well.)

See information from your Exchange global address list. People now integrates with contact information stored in your employer’s Exchange global address list (GAL). This information is displayed on the contact card for each contact.

Filter your What’s new feed by social network. You can now filter the What’s New feed by social network.

Post to your friend’s Facebook wall. In the current version of the People app, there is a What’s New box on the Me view which lets you post to your own social networks. In the new version, this box also appears on your contact’s contact cards, so you can post to their Facebook Wall directly from the app.

Better navigation. As with Windows Phone's People app (and other interfaces on Phone), you can tap a letter in the contacts list to get a quick navigation screen so you can move more quickly by letter through long lists of contacts. (Thanks for the mention of this new feature in the comments below.)