ABC confirms Ann Romney, wife of Republican presidential candidate Mitt Romney, will be filling in as guest anchor for Robin Roberts on Good Morning America during the 8 AM hour on October 10. She joins the list of other co-hosts, including Steven Colbert, the cast of Modern Family and Jessica Simpson, who have filled in for Roberts since she went on medical leave at the end of August. Network sources say GMA producers are also in talks with First Lady Michelle Obama to fill in for Roberts, but there is no time in her schedule right now.