"You're hearing it here first," Valentini posted on Twitter. "Kassie DePaiva's Blair will visit GH this summer!"
"Wow! I didn't even know, Yay!" Alderson said in reply to Valentini's announcement.
DePaiva previously appeared on General Hospital in March 2012 as part of the show's efforts to win over One Life to Live fans who were still reeling from the show's January cancellation. While DePaiva exited the show later that month, several OLTL characters -- including Alderson -- remain part of the GH canvas.
DePaiva debuted as Blair Cramer on One Life to Live in 1993. In 2005, the actress earned a Daytime Emmy nomination in the Outstanding Lead Actress category.
Valentini didn't reveal when DePaiva will first air.