Other Mirr stuff from the Preview:
Different Equipment that grants First Strike, Trample, Double-Strike, and Ophidian. Slagwurm Armor gives +0/+6.
A "Beefy Flier" with Affinity for 5U. There is an Affinity Counterspell. A 4-mana Artifact creature named Frogmite is a 2/2 with Afinity.
There's a Ray of Command/Fling as well.
Imprints give the option of Mana Acceleration, Damage Prevention, and Sorcery-copying.
There's a cycle of Mana-producing Myrs, as well as an Artifact that produces Myr Tokens "if you fancy stripping an artifact or 20 from your deck."
Clockwork creatures come back, using +1/+1 counters instead of +1/+0s. There's the 1-mana 2/2 Clockwork Beetle, to the 6/6 Flying Clockwork Dragon. Artifact Lands do exist, one for each color. There are five Golems, one for each color (Bosh might be one of them. Speculation by me). There are five Shards that are "cheaper to use with the proper-colored mana" that have super abilities like reanimation and pinging. There are also "Spellbombs" that are 1-mana artifacts that "Deal 2 damage, bounce a creature, force a discard, animate a land, or gain you 5 life."
The White Tranquility is called "Tempest of Light". "Rule of Law" is a white card similiar to Arcant laboratory. Viridian Shaman is a functional reprint of Sex Monkey. Annul, Shatter, Detonate, Creeping Mold, Brown Ouphe, Dragon Blood, Stalking Stones, and Ornithopter are all a part of the 16 reprints. There's a new Enlightened Tutor and a "Fixed" Voltaic Key.
Krark's Thumb is a Legendary Artifact that lets you reflip Coin Flips.
The Zombie Race is called the "Nim". Most of them get +1/+0 for your Artifacts. There is a new Drain Life. White's Human race is called the "auriok" and Black's is called "moriok". There is a card called "Auriok Steelshaper" that when equipped pumps all Soldiers and Knights.
There are Elephants, Rogues, Shamans, Drones, and a cycle of Sliths that act similiar to Whirling Dervish in that they get bigger when they deal combat damage to a player. There's also a race of Cats called the Leonin, and one of their equipment grants +1/+1 and Flying.
There's 142 Artifacts in the set.
