With regard to the re-skin there was quite some external interest in this around 2009. Wired Magazine asked several leading designers to present their version of Craigslist redux.

http://www.wired.com/entertainment/theweb/magazine/17-09/ff_...

An article in the same interest, "Why Craigslist Is Such a Mess" ( http://www.wired.com/entertainment/theweb/magazine/17-09/ff_... ).