And no, webworkers don't cut it, because they don't support structural sharing of immutable data structures in an efficient and flexible way.
https://blog.mozilla.org/javascript/2015/02/26/the-path-to-p...
This means the MVP wasm likely includes threads (same timeframe, later this year), and post-MVP wasm can go for full-strength pthreads.
And no, webworkers don't cut it, because they don't support structural sharing of immutable data structures in an efficient and flexible way.