Opening/saving formats:
* Import of audio from QuickTime (mov, aac, m4a) files is now
supported on OSX
* Metadata may be added to OGG files
* Improved export option selection
* Importing of Broadcast Wave Format (BWF) wave files now tolerated
* Additional export options added to MP3 and FLAC file formats
* Command line exporter now supported on Windows and OSX

Effects:
* EQ effect responsiveness improved
* Several enhancements to the EQ Effect
* Batch support added for the EQ effect
* New Auto Duck effect
* Added previewing to AudioUnit effects
* Much improved Noise Removal effect
* Effects previewing may now be canceled
* New DTMF Tone Generator effect
* Additional options available in Noise effect
* Improved the Tone Generation effects

Other features:
* New built-in screen capture utility
* Major speed improvement in Spectrogram rendering
* Increased support for drag and drop on OSX
* Support added for building against wxWidgets 2.8
* Support opening multiple Audacity Projects at once from Explorer on
Windows
* Improved main window sliders
* New support for snapping while selecting and sliding
* Improved track focus handling and visual feedback
* Speed improvements and handling of resizing/zooming in tracks
* Spectrum view may now be zoomed
* New internal file cache to improve handling of project files over
networks

Also:
* Many improvements to language specific translations
* Numerous stability improvements

Changes in 1.3.1 and 1.3.2:

o Improved accessibility for the visually impaired
+ Improvements for screen readers, accessibility of
tracks, and hot keys
o Usability improvements
+ New selection bar
+ New features for label tracks
+ Improved toolbar docking flexibility
+ Menu renaming and reorganization
+ Selection, ruler, and playback control improvements
o Auto-save and automatic crash recovery
o Many bug fixes and stability improvements
o Major improvements to some built-in effects (Repair, Equalization)
and fixes to others
o New features and bug fixes for Nyquist
o Restructured Preferences dialog
o Improved batch processing
o File format export improvements
o Timer recording
o Intel Mac support