[missblit]

Rollback proof bugs are rare, but boy howdy are they exciting. I think I've only seen one so far (unless you count bad data / bad state that persists after a bad change is rolled back... which can also be pretty exciting)

[Andrex]

Is "exciting" a synonym for "harrowing" where you're from? :P

[vitus]

Chrome web store has no rollback strategy, there is only roll forward :(

[joshuamorton]

You can build rollbacks out of rollforwards, although it certainly isn't particularly fun. You patch an update to version N version code so that it's higher than N+1 and roll out the N+2 labelled N.