I think one big use of blockchain like tech will be in XVA [1], specifically CVA. The faster you settle, the lower the counterparty risk and funding requirements. There's good article (admittedly from a biased party) covering this in ibtimes [2]
The problem isn't fundamentally changed by having transactions on a blockchain. You either ask the blockchain who has what assets, or you set up some other system to do the same. The problem isn't that they need the information distributed, that can be done by any number of existing technologies.
[1] http://www.risk.net/risk-magazine/opinion/2422606/-smart-der... (not sure if this is paywalled or not)
[2] http://www.ibtimes.co.uk/setls-peter-randall-says-banks-bloc...