I already run Julia and Haskell on IPython Notebook 3.0 - does the current 4.0 make it simpler to add kernels?
Yes 4.0 is suppose to make it so that the kernels are much easier to install and work with. I haven't been home to install it on my Linux boxes nor the Linux boxes at work. Only thing I can try is Windows and well I HATE working with Python in windows.
I think that if people will let the name iPython go we will see an explosion of usage by other communities and see new features added to the project.