[ProblemFactory]

Yes, that is sort of Linus's plan: http://marc.info/?l=git&m=148798319024294&w=2

> You want to have a model that basically reads old data, but that very aggressively approaches "new data only" in order to avoid the situation where you have basically the exact same tree state, just _represented_ differently.

> That way everything "converges" towards the new format: the only way you can stay on the old format is if you only have old-format objects, and once you have a new-format object all your objects are going to be new format - except for the history.

As soon as there is one new-hash commit in a repo, all users of it will have to upgrade their git client - and that git client will (probably?) default to writing new-hash commits.