Don’t do it Sarah. Snub the Oprah.
Oprah's show is exactly where Sarah needs to appear. How else is she going to reach voters who otherwise would not see her? You don't think the average Oprah watchers are FoxNews hounds, do you? I know only a few regular watchers of Oprah, and they probabably would never see a conservative politician unless that politician appeared on one of these shows.
Sarah doing the Glenn Beck show is preaching to the choir. Sarah doing the Oprah show is introducing Sarah to some who have only seen her as the subject of an SNL skit.