I am a heavy Vim user and it frustrates me when something doesn't work well in my favorite text editor. For this time, my templates were not displayed perfectly and Vim's auto-indenter was confused by the new syntax so it looked pretty bad even with the mustache/vim-mustache-handlebars installed.
So, learning some VimScript from
:h syntax and VimScriptTheHardWay book, I
managed to fork and fix some syntax highlighting issues, implement folds for
block-helpers, fix auto-indenter (by borrowing some code from
othree/html5.vim) so block-helpers tags are respected as well as other html
The result can be seen on Slava/vim-spacebars.
P.S.: the theme is Tomorrow and you can get my fork of it for Vim on Slava/vim-colors-tomorrow.