They are not doing it effectively, because Yahoo ignores it, and who knows, maybe Google will as well in the future.

It is quite possible what Google will do is just use a historical snapshot of links, including all the spam it contained.

I think the person an idea originates from is a relevant result. It might be less relevant than the Wikipedia entry of compiled works, but they certainly deserve a position higher than 50th in the SERPs for their original idea.

I don’t believe forcing change in algorithms is such a good idea. The way things are a link to Wikipedia means something, just like a link out to related sources.

It seems Wikipedia are hoping that links from them will become devalued. The best way to do that immediately is to reduce the value and relevance of a link to Wikipedia, then they have less juice to pass on.

In many ways the search engines should treat Wikipedia as a bunch of rehashed duplicate content, linked to automatically simply because it can be done without much care.
I am sure they devalue a lot of the links to Technorati in the same way, who also use nofollow for outgoing links.

Wikipedia almost gets linked to now by default, simply because they are already at the top of the search results on every search.

The fundamental question there is, ‘does this make the search result more or less relevant to the user’, not ‘does this search result credit the right person for an idea’?