I don't think using Emacs can improve one's programming skills, I don't think some famous people used Emacs before can provide something, either. But these famous people encouraged me to learn Emacs when I wanted to give it up. Here I created a list of famous Emacs users.
Most of people in this list are not famous because they developed or used Emacs, but they are famous and also use Emacs.
Joe Armstrong -- Erlang's author
In The Setup, Joe mentioned that "I write books using XML markup in emacs (nxml mode)" and "I write code in Emacs".
Amelia Andersdotter -- Politician
In an interview, Amelia mentioned "but I do still use Emacs and org-mode"
Steve Brust -- Author of Wad Taltos
In My Own Kind of Freedom, Steve mentioned "“the book was written in emacs on a box running Mandrake Linux"
Vernor Vinge -- Author of True Names and A Fire Upon the Deep
In an interview, Vernor introduced his work environment, obviously he was using Emacs.
Whitfield Diffie -- Security expert, Diffie-Hellman key exchange
On Hacker News, jf said : Whitfield Diffie is also an Emacs user. I once sat behind him at an awards ceremony and was able to observe him hacking on Emacs lisp during the event."
Marc Andreessen -- Mosaic browser autho, Netscape founder
Here is Marc's profile on EmacsWiki
Richard Gabriel -- Author of Worse is Better
Gabriel is initiator of Lucid Emacs.
Guy Steele -- Author of C: A Reference Manual
Steele is one of the authors of Emacs.
Peter Norvig -- Artificial Intelligence expert. Author of Design of Computer Programs
In an interview, Norvig mentioned : "I dislike all three major OS – Windows, Mac, Linux. I like Python and Lisp. Emacs"
Jamie Zawinski -- Mozilla and XEmacs main contributor.
Daniel Weinreb --Founder of Symbolics
Daniel Weinred was a pioneer of Lisp and Emacs
Julian Assange -- WikiLeaks founder
A code snippet authored by Julian Assange.
Mark Zuckerberg -- Faceook founder
In the movie The Social Network, Mark used Emacs to edit PHP and Perl scripts. He also mentioned in his blog : "“it’s definitely necessary to break out emacs and modify that perl script”
Guido van Rossum -- Author of Python
In an article about Python user experience, Guido mentioned : “I am mostly an entrenched Emacs user"
Linus Torvalds-- Linux kernel and Git author
In an article on Google+, Linus mentioned he was using uemacs as his main editor.
Donald Knuth --Author of TeX and The Art of Computer Programming
There is one Elisp code snippet on Donald's homepage: color-mode.el
Richard Stallman --GNU Emacs author.
Hey, Why I am not in this list?