The first new feature is the ability to combine the By Amount and By Size split types. I've been thinking about adding this for a while, but when a user emailed and asked for it, I went ahead and did it. In the future I may look into the ability to combine with other split types, but some just wouldn't be good for doing so.
The second new feature is the introduction of a new split type, By Date. When splitting by date, you choose either the creation date, last modified date, or last accessed date. Then you choose the unit of time to split by. The four options are hour, day, month, and year. (As a disclaimer, some operating systems and programs are horrible about updating file timestamps, so unexpected results aren't due to my programming)
There's one last little feature I added, which is that Folder Axe will remember the folder you chose last, and will start the folder browser dialog from that position during a session.
There was also a bug with the File Type and File Group split types which would process extensions in uppercase differently from lowercase. This has been fixed. Thanks to Eruz from PCWorld.com for pointing this out in your review of Folder Axe!
All of these features were submitted by users, if you have an idea, submit it using the contact form!
Enjoy Folder Axe version 4.0! Here's a link to the Folder Axe Changelog, which can also be found in the Readme file.