Is there a timeline on Valhalla? I only loosely follow the Java ecosystem these days, but Valhalla is of particular interest to my performance-oriented mind.
I follow up on valhalla every now and then. It looks few more releases away, probably not before next LTS.
That being said, the amount of rigor with which the JDK devs test their experiments is really something to witness. Its equivalent to old school MS with painstaking maintenance at backwards compatibility, all the while moving the wheel of progress.
Every single change so far has been planned with a decade of advanced planning because that's just how this ecosystem roles.