Is it possible to present Markdown rendered in an Emacs buffer using Emacs\' own buffer text formatting capabilities? Emacs in graphical environments has rich text presentation
Apart from pretty-lambda (which has already been suggested multiple times), you could look into org-mode and its syntax highliting rules. In particular, the org-hide-emphasis-markers variable does more or less what you want (see e.g. how org-do-emphasis-faces hide markup characters).