CB 3.x will be the beginning of this. Once CB Activity 6.0.0 is done I'll be doing some updates to our product pages, improving our SEO, and adding JED listings for all our products and once that's done I'll begin working on CB 3.x
Right now the plan for CB 3.x is a gradual implementation. The idea is to start with either Slim or Symfony skeleton app and gradually shift CB 2.x into CB 3.x through newer modern APIs and frameworks. This will be designed from the start to be platform agnostic. The initial platform targets will be Joomla and WordPress, but eventually we'd like to support Standalone some day.
I expect to get started on CB 3.x probably in June, but we'll see. CB Activity 6.0.0 has been a bigger headache than expected to rewrite, but it's finally getting nearly complete. I don't expect the SEO stuff across our site to take much time.
I don't expect to support WordPress this year though, but likely next year as it will take awhile to shift CB 2.x into CB 3.x as a progressive rewrite and when we do reach WP it will just be core CB as plugins will also need to be redone into CB 3.x APIs. I believe plugins should be easier to transfer over though as 99% of them already are platform agnostic as they use zero Joomla API.