Actually, I just re-read the title to your post and I'm a little
unclear on the question now. Are you considering using Bootstrap
itself or creating a similar theme for Mulberry? Since Bootstrap is in
Less and Mulberry uses Sass, using Bootstrap itself could be a
problem. It could be handled as a separate stylesheet, but it would be
pretty confusing to have some styles in Less and some in Sass. If
you're talking about creating a Sass Bootstrap-esqe theme for Mulberry
in Sass, then by all means, my previous response stands. That would be
sweet. There are some existing Sass implementations of Bootstrap on
github, but I haven't used any so I don't know what their quality is
or whether they'd be helpful.