The most recent update to Steam’s beta client adds the long-requested feature of installing multiple games at the same time.
The news comes directly from Steam Database (over on Twitter), and in response to countless complaints of having to manually add and queue installs in the past. The new feature allows multiple owned titles to be selected simultaneously and then clumped together in a separate window, allowing the list to be modified a final time before mass installation begins.
To access the feature immediately, you will need to enable the Steam client beta program in your launcher, which can be accessed via account settings. Fortunately, the ability to hide the guilty pleasures and terrible purchases of your library is already available in the commercial version of Steam.