Octave is approaching Version 4. On the way to that major build, Version 3.8 was released recently and features a GUI, which is something many users were waiting for. A Windows build (which is also available as portable version (!)) can be found here.
However, there are still some flaws which should be fixed with the next major release. For instance, I was not yet able to tell Octave how to use Ghostscipt for graphics export properly.
On the other hand, to me, everything feels right and with a strong Matlab-IDE flavour. In other words: I am quite enthusiastic about the new GUI (which is a giant improvement compared to qtOctave, which is dead yet).