Comment from Elliot Swan

That would definitely be cool, though I don't think we have any particular obligation to do so. By the time one has a new design, most comments (both internal or external) about the old one aren't likely to be read much anymore anyway. An exception to this would be if you have an article explaining how to do something (say, JavaScript tooltips). If the only example you give is your own site, what about when you have a new design and don't include your own tooltips? People who do want to use them aren't going to know what they look like. So, for things like that, I think it's important to have a seperate, un-changing example page.