The full list is available on http://www.gnu.org/software/octave/NEWS-3.2.html, but just to mention a few:
- Many optimizations: sorting and searching, matrix transposition, array indexing, logical operators, etc.
- Block comments: this will allow me to easily comment large chunks of code
- Object Oriented Programming: I'm not sure how soon I'll get to use that, but it's nice to know it is there.