The initial report comes from Media Take Out. The site claims that Bey and Jay wanted to choose someone that was not a family member to take on the important role. Since they have supposedly groomed a "close friendship" with Oprah, they asked her. Many people have been wondering who Beyonce and Jay-Z would choose to be Blue Ivy's godmother, but no one expected it to be Oprah.
It's fair to believe that the story posted by MTO may not be 100% accurate. Although no one has come forward to deny the claim just yet, it does seem like a bit of a stretch to have Oprah take on the role. As for godfather, rumor has it that Jay-Z's best friend Tyran Sith has reportedly been asked (not Kanye West, which was also rumored). However unlikely you may deem these choices to be, it may take months for the public to learn who Blue Ivy's godmother and godfather are. Beyonce and Jay-Z aren't going to share their private lives with the world—they never have, and it doesn't seem as though they will start now.

source: examiner