Basically, my idea is that a BTC holder who is scared of losing BTC from hacks or Mtgox style losses (which seems to be the majority of bloomberg viewers), why cant they lock their specific coins to their account so that they cannot be transmitted to another account with out the user unlocking them (ie the blockchain system would simply reject the particular coins attempted to being processed until they became unlocked from their account - maybe i misunderstood how blockchain works exactly?)... the lock could be opened with a phone call/escrow like human to human system with verbal passwords (or whatever 2/3 factor level security desired by the user or that the company is prepared to offer), but the crux is that the coins are essentially untransferable from the holders account, even with the usual account username/pw access (be it wallet or exchange etc). They need to be unchained from the user account to actually be used.
This is what the private key does. Signs transactions for money you are willing to spend. Without the private key the coins go nowhere.
The problem is if you give your coins to someone else (such as the Mt Gox or Bitstamp) you lose control of them (i.e. their private key can move this coins not yours). Then you have to trust them and their systems. Many of these have 2 factor authentication which should protect you from most password attacks. But that doesn't help if the problem is the exchange itself like it was with MtGox.