[mateuszf]

> I have yet to see an "improvement" on callbacks, whether it's promises or fibers or generators, where the benefit in readability is worth the havoc it wreaks on my ability to debug the program.

Chrome has support for debugging async code - for example you can step from one code block to the code in callback as if it would be executed sequentially. So the 'debuggability' is a problem which could be solved on the side of the tools. Of course the case where there would be one single standard for handling async would vastly simplify situation for the tools developers.