Why was iswitchb removed from GNU Emacs 24?

I have used IswitchB for a number of years, but in version 24 of Emacs, it has been removed. My muscle memory is finding the transition to Icomplete or Ido difficult.

I know that it's possible, at least for now, to download iswitchb separately and get it to work with Emacs 24. But before I do that: why was iswitchb removed from Emacs? Will I be doing myself a disservice if I continue to use iswitchb?

IswitchB has not been removed. You can continue to use it, with no problem. It is considered by Emacs Dev to be obsolete, and Icomplete is its suggested replacement.

This action was taken because Stefan felt that Icomplete had been sufficiently enhanced that it can now do what IswitchB does. You might agree or disagree, but as far as I know that was the reasoning.