If you've been playing with the Windows 8.1 Preview and trying out some of the samples, you might be asking where certain samples have gone off to from the Windows 8 SDK.
In some cases a sample has been renamed. The "FlipView control sample" for Windows 8 is now the "HTML FlipView control sample" in the 8.1 SDK. Similarly, the "HTML ListView loading behaviors sample" became the "HTML ListView incremental loading behavior sample" because certain features of the ListView have been deprecated.
In a few cases the sample has been removed entirely, such as the "Snap sample," because the feature is deprecated or no longer exists in 8.1, with new samples taking its place.
There are also, of course, quite a few new samples for 8.1 features.
But there are a few cases where a sample is not present in the 8.1 Preview SDK, but you can't find anything that suggests the feature it demonstrated is deprecated or anything like that. What's happening here is that certain bugs in the Windows 8.1 Preview build broke the sample, and so instead of shipping a sample that doesn't work, Microsoft simply didn't include it in the Preview SDK. You'll see them reappear in the SDK when the RTM build of Windows 8.1 is done.
Be sure, then, to download the sample again after RTM so you'll have the proper set.