If I understood Jeff Hagins (CTO) correctly on the last Developer Call, Hub V2 is now expected for release on July 1st, 2015, with Beta units already released to internal staff, and other limited release Betas to select customers between now and then.
The Platform on Hub V2 “looks” the same to the user, but runs in the expected distributed architecture (i.e., all SmartDevice Handlers and SmartApps that can run independent of the Cloud, will run in the local Hub V2). This includes scheduling. The Mobile App still requires the Cloud but someday a local connection may be provided. Event logs will still be stored on the Cloud, but these will be in an asynchronous message queue.
The above is highly paraphrased. A recording of the call will soon be posted, I presume, reference: