Yes yes a million times yes. I've looked at Sass before but its HAML syntax made it less than appealing. This is beautiful, its just a smarter CSS, leveraging everything you already know about CSS but with the things you wish CSS had.
This is just a simple enough extension to CSS that is natural, but still giving power to express styles much more concisely.
Chris Eppstein, the inventor of SASS has stated elsewhere that one of his primary goals is to make SASS friendly for designers to use, and he claims to have sought feedback from designers as well. See comments here : http://jeffcroft.com/blog/2009/may/20/applying-oop-concepts-...
Everyone seems to give designers an insultingly small credit for their ability to do development. But the concepts behind CSS and Sass are the hard parts (flow, positioning, block, layout, etc), the syntax is easy in comparison. Every designer that I've worked with who knew css took 1 hour to learn sass and fell in love.
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... looks like a good compromise of SASS though. I might jump!