indyank - 5:37 am on May 13, 2012 (gmt 0)
As I see it, the theme creator's link should be ignored if it's there.
Tedster, I am referring to only those theme creator links and not of any other type that you have described above. But theme or plugin creator links that link back to the creator site with brand name or author name other than any keyword shouldn't be penalized. But they appear to be penalizing wpmu.org.