I haven't played Domination (or with any of the new cards) yet, but I can't help trying to analyze the new format and predicting strategic trends. Let me know what you think.
Here is my thinking so far:
In Domination, cards that specifically address mana economy will not be as strong. Games won't be able to go as long, so the long term mana advantage will be less significant. Plus setting yourself up to secure orbs will accomplish much the same thing while also directly contributing to a point victory and strengthening your defensive position with a stronger board position and the option for healing if you need it. I can see a spawnpoint + Meditation Amulet strategy working, but I have trouble justifying using Mana Crystals in Domination.
It's harder to predict the effect on the viability of action economy cards like Battle Forge, Fellella, and Lair than Mana Crystal. I expect creature spawnpoints to be relatively strong. Playing one will slow down securing your first orb by about a turn, but you should be able to make up for that with a stronger position later, particularly if you can secure multiple orbs and use them to generate the mana you need to keep a steady stream of creatures coming.
Whether aggression or control will be favored will depend largely on how easy it is to get at the other mage and how easy it is to get enough points to win through orbs. In general, having neutral creatures out, gumming up the board and hindering movement will tend to slow down aggression, and focus creature rushes on flying and elusive threats. Having other obstacles start out on the board will tend to hurt aggression further. In addition, a system that encourages early creatures for economic plays puts control in a stronger position to resist a creature rush. The ability of the orbs to grant healing means that it will be harder for an aggressive player to secure a kill against an opponent that controls multiple orbs, and the control player in this circumstance doesn't need to fully stabilize to win, they just need to hold onto those orbs and delay long enough.
That said, I expect most games of Domination to start with both players trying to secure an orb advantage. I anticipate that most games will end with one player conceding the point race and going for the enemy mage when it becomes clear that they will lose the points race.
Domination will encourage builds with multiple creatures in order to remove orb guardians and secure orbs. I expect this to strengthen ranged creatures and bows, since they can weaken orb guardians (whether the original neutral ones, or the ones your opponent uses to secure their orbs) without suffering from the counter attack, and the action will tend to be more spread out. Things certainly could spread out in a standard Arena match, but there are more incentives to spread out in Domination.
Position control will have additional uses, but it's hard to tell how much more important it will be. Regardless, mobility will be more important, and slow creatures like Darkfenne Hydra, Iron Golem, and Devouring Jelly will be weaker.
In terms of specific mages, I expect the Johktari Beastmaster and Bloodwave Warlords will be significantly stronger in Domination because they will always be able to take advantage of their Wounded Prey and Veteran abilities respectively, whereas in a standard Arena match, there were matchups where those abilities were marginal or even completely useless. In particular, I want to try a Bridge Troll opening with the Bloodwave Warlord. Veteran Bridge Trolls sound amazing.
I expect the Forcemaster to struggle a bit due to the lack of a strong creature base, though I'll have to try playing a few creatures with her and see how well she can secure orbs. Force Pull should be extremely helpful in Domination, but the high cost of solid creatures could easily prove crippling.
I expect Warlocks to play more creatures than in standard Arena. Pentagram should be getting a significant boost in Domination due to the earlier combat with neutral monsters and the addition of Sslak to the creature base. One of the reasons I haven't been enamored of Pentagram builds is the lack of a solid level 2 creature with strong defensive stats for it's cost. I haven't been impressed with Infernian Scourger in that role, but I can see Sslak being a reasonable choice, particularly with how well they work as orb guardians. Costing 2 less mana for the same stats minus counterstrike and and flame -2 leaves you in a better position to do something with your mage while pumping creatures out of the Pentagram. I don't expect to see Usslak coming out of the Pentagram because Dark Pact Slayer is much more spellbook efficient, and for only 2 more mana offers better synergy for either Warlock.
