For now, Samsung is following the cookie-cutter approach to apps and relying mostly on the Android Market.
There is a Samsung app store on the Samsung Galaxy Tab 10.1 but the apps mostly repeat what you will find in the Android Market. Which is to say: not that many apps that are optimised for Android 3.0. Even though the Motorola Xoom was first out of the gate in early March, the app selection is still not brilliant - it is improving all the time though.
You can install many of the Android apps designed for phones, but many of them won't make the best use of that 10.1-inch screen. And one good thing here is that if your device is just plain incompatible with a certain app, it won't let you install it.
You will find a few new additions in the 'specially designed for Honeycomb- app selection, though: a Twitter client called TweetComb, a few new games including Pinball HD, the new Google Music app that adds cloud storage for your audio files and a few extra newsreader and news aggregator apps.
That makes the app selection for the Samsung Galaxy Tab 10.1 slim now, with the possibility of being slightly better in the future. However, Android tablet apps are few and far between compared to the wide selection of Apple iPad apps.
You won't find many video chat services (other than Google Talk), a Skype client, a wide selection of games beyond the dozen that are currently available or anything like a slideshow or page layout app. There's no music recording apps, few notetaking or journaling apps and only one Twitter client.
There is an HD version of Angry Birds, a good flight tracking app, an RSS aggregator called Pulse and a Dropbox client. This is apart from the standard Google apps for Gmail, calendars and some funky additions such as Google Body (search for body parts), Google Sky Map and Google Earth.
Samsung recently released the Social Hub app for the Galaxy Tab that was not available when we tested the device originally. The app lets you view feeds from Facebook, Twitter, and LinkedIn. In the feeds view, the Tab added status updates quickly and showed posts from all service sin one long thread.
There is also a Messages section, and all of our Twitter direct messages, and all Facebook and LinkedIn messages, appeared here according to the day of the week (today, yesterday, and then previous dates). This made the Social Hub exceptionally useful for a quick peak at social activities. You can also post a status update for one service at a time (but not multiple at one time). The app has no reporting features and no way to schedule posts, so it is not exactly a HootSuite competitor.