Emacs AFAIK can do all those things, with different degrees of integration depending on the language. For pure C, for instance, Emacs has always been the "IDE" of choice for years in UNIX(ish) environments. Thanks to Clang C++ is now covered too. For Lisp languages there is simply no other option. Even scripting languages like Python, Perl and Ruby have all got fantastic integration, and their modes keep getting better and better because of their open source nature, adding semantic analysis and tools integration.
The package manager makes it really easy to automatise installation and updates.
Sure, its learning curve is unusually high and Elisp knowledge is required for some edge cases, but it's definitely worth in the medium and the long run.
It didn't. Emacs still tries to do most of those things and fails more often than not. I love Emacs and I use it daily, but between it's dated look, monstrous codebase, enormous feature set and limited resources dedicated to development it cannot hope to match programs written for a single purpose by a team of professionals.
Still, Emacs is great editor. I'm not going to dump Org Mode, for example, and calc is great, and scripting is absolutely awesome (Emacs is also great IDE for Elisp) and so on. It's great for many things, and it's even ok for programming, but it's never going to be as good as IDEs. And IDEs are not going to have mail & newsgroup clients built into them, I suppose.
Sure, its learning curve is unusually high and Elisp knowledge is required for some edge cases, but it's definitely worth in the medium and the long run.