I have to admit that between the extensive developer diaries, dev streams, and various previews I've seen so far, it's become very difficult to not be excited for this one. It seems Triumph Studios took a hard look at everything AoW3 and Planetfall did both right and wrong, and have adjusted things accordingly for Age of Wonders 4. Stuff like exploration, hero development, and empire management have been expanded and/or deepened, while diplomacy and the combat system have been refined and improved.
Not that this will probably be a Day 1 purchase for me; I rarely do that anymore. But unless the release is a complete dud, I have a feeling I'll be diving into it sometime this year.