In an interview with GameSpot AU, Jay Wilson confirmed that Hardcore is definitely returning to Diablo III.[2]
Hardcore is definitely returning to Diablo III, but we haven’t decided what sort of special Battle.net features we’ll enable with it. We want to make sure that if you see a HC char on B.net, you’ll know they’re HC. It’s a status symbol, and it’s only one if you know. We’re looking for ways to reward players, and we’re sure we’ll have a set of HC achievements also.