A thread on the Diablo III forums claims a new bug has been discovered to allow Barbarians to regain 8% of their HP per strike, followed by a fairly confusing debate over whether this is genuine, or trolling based on the recent Wizard bug/exploit (thanks Kotaku). Speaking of which, a post on the Diablo III forums has a more detailed response from Blizzard than the brief comment added to the story about the invulnerable wizard bug/exploit in the action/RPG sequel:

We are currently rolling out a hotfix for a recent bug regarding invulnerable Wizards. We will continue to carefully monitor this issue and welcome anyone with information about bugs or hacks to submit a detailed report to our Hacks Team by emailing hacks@blizzard.com, or by completing the Hacks Report web form. In your correspondence, please include any steps necessary to replicate the issue as well as any additional details you are able to provide.