According to her Wikipedia page, Betty White will be hosting the Memorial Day edition of WWE Raw on May 31st. Since Wikipedia can be edited by mostly anyone, this should be taken only as a rumor until either WWE or Betty White herself makes an official announcement.
The New York Times has posted a new article praising WWE for its switch to PG TV and for its Raw guest host concept. The following is an excerpt from the article:
"In a bid to capitalize on that audience — an average of 5.3 million viewers each week, many of them male and teenagers, according to Nielsen Media Research estimates — the producers of “Raw” decided last summer to begin booking celebrity guest hosts.
Those who signed up early included Jeremy Piven of “Entourage,” who insisted on climbing on the turnbuckle of the ring to fling himself onto the WWE performer John Cena, and Donald Trump, who could not resist an on-camera shouting match with the WWE chairman, Vince McMahon.
Other boldface names who have climbed into the “Raw” ring are the singer Jewel and her husband, the rodeo star Ty Murray; Bob Barker, who presided over a WWE-themed “Price Is Right”; Dule Hill of another USA series, “Psych”; Carl Edwards, the Nascar driver; and Nancy O’Dell and Maria Menounos of the entertainment news show “Access Hollywood.”