We only need testing, lots of it. The main new features are the support non-unique resource IDs that will help a lot in POP2 resource importation and the index names are now in forwards and may be bigger than 4 letters, much easier to understand.
Other less important new features are the new option --format (to generate filenames with the name specified), and the new dat input syntax allows to extract more specific resources like for example "rooftops.dat@400:shape#second,401:shape" and the unknown.xml file is now all merged in the extracted main folder.
If you want to test it, please make a post in the forum.