UPDATE: interface scaling is not supported, starting at 1.4.12.
This affects Windows users only. While there is not a permanent fix, the workaround is to override the DPI settings for Maya.
1. Go to your maya.exe file (located somewhere in <Program Files/Maya version/bin>, right click and open up its properties.
2. Go to compatibility tab. Click on Change high DPI settings.
3. Edit the settings as shown below:
Further information about this issue: