True to his word, Philip Rosedale and team at High Fidelity are hiring a C++ engineer to implement the company's plan to register user-generated content on a blockchain:
The company plans to use a public ledger and digital certifications to support the management and tracking of items users register with the company. This blockchain-based system will enable a marketplace for the sale of digital assets with certs showing their provenance and ownership.
You can read more about Philip's vision here and also (mainly) here. Of course, the fact that the company is hiring someone to do this now suggests this blockchain won't actually be publicly available for at least another quarter or two.