Anyone with beta actually got a chance to do some tests? I really wonder how damage taken relates to fury regeneration. Both in terms of how much of your fury generation will actually come from damage taken rather than fury generators, as well as whether damage reduction will reduce fury generation from damage taken, or perhaps instead actually give you the same fury while still taking less damage, thus allowing you to tank more and gain more fury if your defensive stats are good enough.
At least the DR question should be easy to test with some defense gear. Wear it and count how much fury you gain before you die (or reach X% HP). Take it off and repeat the test.
I suppose figuring out how much fury you actually gain per point of damage taken is harder to figure out, since it's probably also dependent on monster level.
There's also a small chance that they just made it based on hits taken rather than actual damage amount in order to avoid needing to worry how it scales with stronger enemies and with damage reduction, but then again probably not since it will cause new problems (many weak monsters generating much more fury for you than 1 big monster that deals equivalent damage).