3.93 is released! Since this is a new Sony firmware it is not homebrew compatible. Wait a little while and a new M33 will released which will allow homebrew on the latest Sony firmware. 

The main 3.93 difference is:

“…users of the PSP Internet Radio feature will find 20 new internet radio players to enjoy. The new players are organized into more specific styles of music so that PSP users can easily find what they are looking for and listen to their favorite genres.”