Currently there isn't a very good delegation market... by that I mean a DEX. Implementing the ability to delegate RCs offers new avenues to remedy some aspects of this problem but not all of it. This architecture allows Steem to support decentralized smart contracts via consensus, with out a central third party holding funds or unnecessary bloat to the overall design of Steem. When RC delegations do arrive they will fit better in to this paradigm for disbursement than anything that is planned that I'm aware of. And can be easily extended to build an RC DEX for other reasons than new onboards.