Preprocessors aren't incompatible with components. I usually structure my frontend code like

    components/
        widget-one/
            template.html
            script.js
            style.css
        widget-two/
            template.dust
            script.coffee
            style.styl

And then the style file for a component is completely scoped to that component's main class:

    .widget-two {
        .widget-two-control { color: blue; }
    }

The build script can handle each component separately and stitch the results together. Just because SASS/compass encourages a monolithic style doesn't mean it's necessary.