I’m not sure that Google expressly says that they don’t give value to any nofollow links whatsoever. I think there are studies out there where sites have gotten themselves ranked simply from a Wikipedia link. My opinion on nofollow is that it is a flag for Google to look at and then decide if the link has value or not, but I don’t have any empirical information on this. For example, a nofollow link from a blog comment (the reason nofollow was invented) would certainly not be given credit. I could easily believe that Google credits Wikipedia links since that is a human edited website and human edited content is very important to Google.
That said, it is impossible to get a link on Wikipedia if you don’t have real and very high quality unique information that the Wikipedia community finds valuable.