The guy did a follow up video of the nation he played in the first 1 hour video:
http://www.youtube.com/watch?v=s_HsP2oSb2g
He even plans to make more videos to show the different nations/leaders to start with. Very impressive.
I don't get it how they plan to balance it for multiplayer with that randomness. I mean, one location gives you 5 rubies out of 6? And if you don't have random gods on your side, you can't summon shit? Scouting is with leaders only, and Necromancer wasn't able to get any scouts for entire game in the video (so to know what the hell is going on around). So how exactly can you plan what to do with your main army without scouting?
Dominions is still worth buying if you plan multlayer. Its not worth single player at least for me. The Game is so complex and so much possibilities with all the spells and items so its more for learning the game.
MP is fun because you make only 1 turn which takes a lot of time mid/lategame. This turn is hosted usually every 24/48 hours. Causing real fun with for example 20 players playing different nations in same game. A game lasts between 50-100 turns, depends on settings. This cycles are perfect for MP
I like the mechanics, and i really wanted to try it several times, but from AARs and videos it seems you're mostly fighting:
- HORRIBLE UI. Just look at the Mortal Combat with UI that people do so to make a communion for example (they say it takes an hour+ to setup, and then 5 minutes to watch a fight), or so to steadily transfer troops from the back to frontlines etc. And it's micro-crazy, just count a number of clicks per one decision (i tried a demo).
- Lack of proper documentation. You get combo spells and interactions like in Magic: The Gathering, yet game descriptions are worse than in ancient Master of Magic - either they have unclear wording or they don't explain half of the thing at all.
Because of that micro-happy UI you can do one turn in one game per evening, right? At least that's what AARs say. So 2 months for a 50-turn game? And you MUST read, like, all forums and wiki's so to be at least at noob-level in MP (because it's extremely noob-unfriendly with no proper in-game documentation)? You need some crazy dedication to pull that through, i certainly don't have it. Very good game mechanics wasted, oh well.
And they never did a decent AI (at least release AI source code to public, like in Civ 4, damn it, if you don't want to do it themselves!). So singleplayer is useless as well.
The only good thing of Dominons 3 is that a good AAR with all these combos and strategies is interesting to read even if you don't know the game at all. That is, when you don't need to fight the UI and manual by himself, and can just look at the results

I mean, just look at that AAR
http://lparchive.org/Dominions-3/, it has all in one - it mentions horrible UI, how much it takes to play the game, lack of documentation etc. But it's interesting to read, yes. Basically, if you're not sure you can stick to Dominion 3 for at least a year of your life and that you want to spend more time reading forum posts/guides than playing, you shouldn't even try it.
P.S. It's perfect for MP when you can finish the game in one 25-minute session - that's why RTS and even DoTA-like matches are trying to fit that niche. Even 2-4 hours per Civ 4 ladder game is too much. In Dominion 3, 2 months somehow becomes perfect? LOL?
I think Spectromancer has one of the best formats for a perfect strategy game (match takes about 7 minutes, it's a Magic: The Gathering idea but completely redesigned for online play).