Windows Esssentials 2012) as of January 10, 2017.
Here are a few questions and answers:
Will the programs still be available for download?
Microsoft has only stated the programs will be available for download until [the] end of support date on January 10, 2017. Apparently the programs will no longer be available after that date. If you are concerned, you should download the offline installer before that date.
Where are the Windows Essentials Offline Installers for various languages?
English (United Kingdom),
English (United States),
What happens to Movie Maker (and Photo Gallery) if it is already installed?
Already installed applications will continue to work as they do today but there will be no updates.
What are the recommended alternatives for Movie Maker and Photo Gallery from Microsoft?
Microsoft has given the vague statement that "Movie Maker will soon be available from Windows Store for Windows 10 users." But so far I've not seen any actual announcement of what that may be. So far I've only seen less powerful apps like Movie Moments in the store without any viable replacement from Microsoft. The suggested replacement for Photo Gallery is the built-in Photos application, but I leave it to you to decide if that is a true replacement or not.
Update: The line about Movie Maker has been removed; as suspected, there is no replacement
What other options are there?
ProVideoCoalition has posted their Free Video Editing Software Guide for 2017.