Even anonymity as strong as Zerocash is not incompatible with strong public auditing of Bitcoin holdings; if anything it improves the auditing situation by making it easy to selectively choose who can audit your activities. I might be perfectly happy with my chosen accounting firm to see all my books in a provable way, maybe even my local government, while still wanting to ensure that criminals and competitors do not see my activities. With a bit of cleverness you can even make these audit proofs non-transferable - that is Alice could provide solid proof to Bob that she has the funds she claims too and her accounting books are correct, yet Bob would not be able to provide that proof to Mallory as either Alice or Bob could have produced it.

And yes, I agree 100% with gmaxwell's comments on the need for privacy. Bitcoin without privacy is simply a non-starter. In many jurisdictions failing to provide that basic level of privacy is even illegal in the context of many financial products, which will prove to be a serious barrier to Bitcoin adoption.