One of the issues commented during the workshop yesterday was the difficulty of involving in our projects volunteer contributors that are interested in design.
The UX community from stackexchange http://ux.stackexchange.com/ may be a good place to get feedback from other designers or design enthusiasts. It is a Q&A site with 15k users and 99% of questions get answers according to their statistics.
We tried this some time ago, and published a question with out initial wireframeshttp://ux.stackexchange.com/questions/21718/which-is-the-best-way-to-select-a-language-from-400-possibilitiesto bring attention to the ULS designs. I think it is a good way to have some additional feedback from a different point of view, but also to make design enthusiasts aware that they can find design-related projects in MediaWiki.org.
Pau