On December 11th, Microsoft released this security update (KB2753842): MS12-078: Windows OpenType Compact Font Format (CFF) driver.
This patch is causing certain programs to break. The Microsoft KB article acknowledges:
We are aware of issues related to OpenType Font (OTF) rendering in applications such as PowerPoint on affected versions of Windows that occur after this security update is applied. We are currently investigating these issues and will take appropriate action to address the known issues.
Well, it impacts more than PowerPoint. If your applications are suddenly experiencing failures, try removing this update to see if it makes a difference. It can be removed from the Control Panel, Add or Remove Programs, under Updates.
Here's a Microsoft thread about the issues people have encountered.
Here's another discussion from Utter Access that includes instructions for uninstalling the update.