You don't think the leap-hour will be a new millennium bug?
When you look at how much people crap their pants over the leap second - a relatively common thing - I dread to think how unprepared people would be for something 3,600 times less common.
Yes, it would be similar to Y2K. Hopefully politicians could agree decades in advance so people would have plenty of time to prepare. Also, since you're only changing the tzdata and not UTC, much less would break and most of the breakage would be purely cosmetic. Right now we have several tzdata changes per year and they cause much less disruption than leap seconds.
When you look at how much people crap their pants over the leap second - a relatively common thing - I dread to think how unprepared people would be for something 3,600 times less common.