Spoilers!

I know, I know, I'm terrible! (All five of you reading this agree!) But it's spoiler season and I love talking about spoilers. So here we go:

Burning-Tree Emissary: This card isn't a powerhouse, but it's one of my favorite cards spoiled so far. Not to denigrate "Meat and eggs--we eat!" but original Ravnica-era Gruul was tough to empathize with for the average Magic player.
One of the biggest psychographic idiosyncrasies in the Magic community today is the misconception of "blue = smart"—perpetuated by the conception that tempo or control mirrors are the only skill-testing games of Magic. It accompanies the mindset that modern Magic is all about "turning dudes sideways," as if combat math and risk evaluation aren't skills that require practice and contemplation. The Gruul guild played into this stereotype with a lot of their flavor text (see Skarrg, the Rage Pits; Gruul Signet; Gruul War Plow; and Gruul Scrapper for an intro on this). Burning-Tree Emissary is a huge change from that mindset—it immediately recalls Wild Cantor, but instead of self-destructing to channel mana, the Emissary carries it with her. Instead of the "smash the guys what have brains" guild, the Gruul become the real champions of nature in Ravnica (the Selesnya want to channel nature, the Simic want to adapt it, and the Golgari want to master it). Honorable mention to today's Uncharted Realms column, Gruul Ingenuity, previewing Clan Defiance, for promoting this new view of the most maligned guild of the ten!

Also, it's probably not a great Constructed card, but it does interesting things like let you have sequences like T1: Champion of the Parish, T2: Emissary, Mayor of Avabruck and swing for 4 with Champion. (You can posit more improbable cases--most notably playing three more Emissaries in the same turn and swinging for 7--but I don't think that's particularly worthwhile.) Naya Humans is already a thing. I don't know if this is what it needs—I sort of doubt it--but it's a potential direction for it. It's also a potential addition to the Battle Hymn/Burn At The Stake decks.

Hands of Binding: A little about cipher, and some about this card (the cipher card with the most Constructed applicability of those so far spoiled, in my opinion). First, I love the ability. I think it's worded awkwardly, but I think they probably did the best they could within the rules. Once you get past the text, it's a very easy-to-grok ability. I'm interested in seeing whether or not it's on instants--I think the power level on instants with it becomes a much more treacherous road. I'm also interested in seeing more generic abilities on it--namely, "draw a card" and "target player discards a card." I'm comfortable with, for instance, an uncommon UU "draw a card, cipher" sorcery. (I think it could probably cost 1U, actually, but I'm trying to avoid pushing it.) It fits neatly between Curiosity and Ophidian Eye. I was surprised to discover that there's no discard variant of Curiosity (although Specter's Shroud from Darksteel is an equipment analog). I think "target player discards a card, cipher" is fairly costed at 1B (and could even just be B) as an uncommon sorcery.

As for Hands of Binding specifically, I think it's a fantastic tempo play that you can leverage into most of a Tamiyo for two mana in an aggro-control shell. Tapping down a defender with the spell to get your attacker through, then using the ciphered copy to freeze their attacker seems really powerful.

I'll talk about more spoilers soon!