The TabView is similar to our current TabPanel control in some ways but there are three important differences:
1. TabView tabs are always along the bottom, whereas in a TabPanel they are along the top. A TabView can include icons or not, though a TabView that doesn't include icons is rare.
2. A TabPanel is a control. A TabView is not. While a TabPanel can be just about any size and positioned just about anywhere on a layout, a TabView must either consume the entire screen (as in the example above) or one portion of a SplitView. The Settings application on iPad is an example of a SplitView.
3. A TabPanel can contain other controls. A TabView cannot. Well, to be more correct, a TabView can contain other layouts which can contain controls.
This brings up an important difference between how you will build iOS apps compared to how you are used to building desktop and web applications today. Because most of the applications you create will be universal (supporting both iPhone and iPad) you will be creating "views" which are simply layouts of controls (much like container controls today) and then dropping those views onto things like a tab in a TabView. This allows you to easily share these views between your iPhone and iPad user interfaces. Consider, for example, that the Settings app on iPhone only shows you the left side (the list of settings) initially. You then tap a setting to see its details. Those details are a separate view. The two views (list and detail) are shared by both the iPhone and iPad versions of Settings. The only difference is that the iPad version uses a SplitView to display both since there's enough screen space available.
These differences won't change much about how you work. After all, a view is pretty much the same as a container control, a window or a webpage. But as you can see, the TabView is a bit different from the TabPanel control you use on the desktop today.
I'll be blogging with more progress as we continue, stay tuned!