Be warned that there are engine changes, and some things will look different or be broken. For example, at the time this blog post was written, Hammers of Fate Campaign 3 Mission 1 (Ylaya's Quest, The Spy) had the Seer's Hut quest broken. In the original Hammers of Fate, you can get a +14 Attack / +6 Defense bonus for completing the Seer's Hut quest at Heroic difficulty. With the mod, that quest is not properly initialized and you do not receive the bonus.
Most mods for Heroes V or Hammers of Fate will still work. Simply rename the extension to "h5u" and instead of the "Maps" directory, put them in the "UserMODs" directory.