I haven't used Node, but I think it's funny how they tout asynchronous IO via callbacks. Meanwhile the BEAM has that plus asynchronous computation - you just write synchronous code and let the scheduler pause your BEAM process as needed.
If you don't have to write code to deal with the computer pausing your unix process to run a different one, and you don't have to write code to deal with the VM pausing your code to run garbage collection, why would you have to explicitly write code to deal with a pause for IO?
If you don't have to write code to deal with the computer pausing your unix process to run a different one, and you don't have to write code to deal with the VM pausing your code to run garbage collection, why would you have to explicitly write code to deal with a pause for IO?