The hefty termination packages that Fannie Mae’s former top executives are now slated to walk away with are expected to generate more than a little attention on Capitol Hill as lawmakers grapple with GSE regulatory reform. Concern about the rewards offered departing GSE executives first surfaced about two years ago, when Wayne Abernathy, assistant secretary for financial institutions at the Department of Treasury, complained that Fannie’s recent filings with the Securities and Exchange Commission revealed…