Technically, a similar case would need to be accepted by the court and one justice would need to change their mind regarding the RKBA. It is unlikely the court would take a case similar enough to Heller to constitute a direct overruling.
Practically, a future decision overruling Heller is highly unlikely. Particularly anytime in the near future. The court loses all credibility if it simply overturns established law whenever a few new justices are seated on the bench. That doesn't mean that the court won't chip away at the ruling in Heller over time...that is possible, but there isn't likely to be a case that will directly overturn Heller anytime soon.
Instead, what we will see, is how well the ruling in Heller holds up when applied to everything else RKBA related; concealed carry, magazine limits, etc.
The possession of arms is the distinction between a freeman and a slave. -James Burgh