It’s now confirmed that Microsoft have Acquired GitHub. How will this affect me? Should I be worried? Do I need to do anything?

I think, in general, this will be good for Github, and for (almost) all their users. I predict simple and improving integration with Azure coming soon.

Who should worry? If you have a (closed source) product that competes with one by Microsoft then you should evaluate the possibility of gaining access to the code and/or meta-data (how paranoid should I be?). GitHub also hosts content that some nations want to censor. Microsoft will be coming under new pressure to remove them.

This has prompted me, along with many others, to take another look at GitLab.com. I’ve been using GitHub for public repositories (unlimited public reporitories), and BitBucket for private ones (unlimited private repositories with <= 5 contributors). I can use GitLab for both of these use cases, and am now migrating my repositories there.