Over the last few days I've noticed that pressing Ctrl-. no longer expanded the Smart Tags in the text editor (used to Refactor Rename or implement interfaces). It turns out FSI steals this combination for Canceling Evaluation.
To rebind it, find View.ShowSmartTag in the keyboard options and set it back to Ctrl-.
Edit: It turns out this is mentioned in the release notes that I neglected to read. Oops.