Just a quickie to say that I released simple a SASS Snippets plugin yesterday. Install it with Package Control or grab it from Github.
Use the name of the snippet, e.g. fade-in for fade-in.sublime-snippet as the tab trigger. If the filename has an @ at the start, ignore it & use the rest, e.g. if for the @if.sublime-snippet. Make sense?
Let me know what you think & if you think I can add to it.