Would Heller be an obstacle to banning concealed carry?
The short answer is no.
Here's the longer answer. Keep in mind that a Supreme Court decision serves as precedent and is binding only as to its holding. The holding of the court in Heller was that the Second Amendment protects an individual right to possess a firearm unconnected with service in a militia, and to use that arm for traditionally lawful purposes, such as self-defense within the home. As a result, the court held that the District of Columbia's handgun ban and the trigger-lock requirement (as applied to self-defense) violate the Second Amendment. Therefore nothing in the Heller holding addresses the issue of concealed carry outside the home.
There is discussion in the court's opinion of the implications of the holding. The court signaled that an argument that the Second Amendment automatically invalidated any gun control legislation was not going to be entertained. In this regard, the court stated:
Although we do not undertake an exhaustive historical analysis today of the full scope of the Second Amendment, nothing in our opinion should be taken to cast doubt on longstanding prohibitions on the possession of firearms by felons and the mentally ill, or laws forbidding the carrying of firearms in sensitive places such as schools and government buildings, or laws imposing conditions and qualifications on the commercial sale of arms. [pages 54-55 of the slip opinion]
It is interesting that the court did not mention concealed carry here, though it had shortly before the foregoing text, which it said:
Like most rights, the right secured by the Second Amendment is not unlimited. From Blackstone through the 19th-century cases, commentators and courts routinely explained that the right was not a right to keep and carry any weapon whatsoever in any manner whatsoever and for whatever purpose. See, e.g., Sheldon, in 5 Blume 346; Rawle 123; Pomeroy 152–153; Abbott 333. For example, the majority of the 19th-century courts to consider the question held that prohibitions on carrying concealed weapons were lawful under the Second Amendment or state analogues. [p. 54 of the slip opinion]
Given that one of the bases for the court's interpretation of the Second Amendment as conferring an individual right is that a number of state courts in the 1800's construed the Second Amendment or state analogues as conferring an individual right, the fact that courts from the 1800's routinely considered concealed carry to be a legitimate subject for legislative regulation is a powerful argument for not striking down modern-day legislation regulating concealed carry.
So, is Heller, in and of itself, an obstacle to banning concealed carry? No. Is the court likely to uphold or strike down legislation banning concealed carry? That's a subject for another post, another day, one that I think will require a discussion of the 14th Amendment and the incorporation doctrine.
This issue is one reason why I do NOT support a National Right to Carry Act by Congress. Let the states do it by reciprocity. It is slow and laborious but much more secure IMHO.