Eric Lander wrote a piece at Search Engine Journal named NoFollow: An SEO Red Flag? which sparked some interesting debate over in a Sphinn thread. The question at hand is, does using a nofollow attribute on many of your links raise a red flag over at Google and other search engines.
There is a lot of debate on if it would raise a red flag or not. Personally and currently, I think it wouldn't make you stand out by using it. I mean, if 99.9% of your links are nofollowed in your site, then maybe it might look incredibly weird. But I doubt Google will look deep into a site just because they use a nofollow attribute on many of their links.
But is it not possible? Historically there was accepted belief that those that deployed cloaking and used the noarchive tag were singled out and hand reviewed based on using the noarchive tag. Many old time SEO experts would swear by it, they may even have dates as to when this went down - I don't have the dates on me at this time. So the concept of using a Google provided tag or attribute that can be used by Google for manual review is not unthinkable. But in this case of the nofollow attribute, I just don't see it being done.
Forum discussion is heating up at Sphinn.