Lava coil, we get a beefed up magma spray!
Insert//invent, first side is meh, sorcery and instant tutor has potential, but is expensive (at least it's instant)
Unless there is something really worth spending 6 mana to get, it will almost always be better in Izzet to just draw cards. Nice that it does 1-up in card advantage though.
Lava Coil is really nice...completely removes the Rekindling Phoenix threat for less mana. Also removes early stompy threats like turn-2 Steel Leaf Paladins or Thrashing Brontodons.
New cards up!
Golgari Raiders - Looks to be a solid threat late game with increasing P/T and especially Haste. But without evasion or trample this is just going to be chump blocked all day long.
Never Happened - Dimir is just looking sick in this set. Loving it. 3-mana to look at their hand, then exile something from it or the graveyard. Pretty sure this is not a Maindeck card but more of a Sideboard option.
Integrity // Intervention - Nice split card. Integrity pumps a critter, Intervention is an expensive Lightning Helix. Both great for what the Boros decks of Guilds is trying to do.
Nightveil Predator - So it looks like this is card 2 of an uncommon theme. UUBB gets you a pretty solid 3/3 Hexproof, Deathtouch Flyer. Maybe not the most constructed playable card, but love the name and flavor text.
Erratic Cyclops - Could this be the second card (after Golgari Raiders) in a 4-mana cycle? A 0/8 Trample creature for 4-mana is bad, but his ability to pump up the attack when you cast instants/sorceries is quite nice. I could see this as a SB card against the Izzet mirror as Izzet usually has problems permanently dealing with high-toughness creatures.
Conclave Guildmage - I have so far liked the Guildmages...that stops here. 1-mana to give all your creatures trample is nice, but in Selesnya most of your creatures should be small so it won't do much good for much of them. And creating a 2/2 Vigilant Elf Knight (nice touch) for 6-mana is uber-expensive. I like the idea of this card but not so much the execution of it.
Price of Fame - Love the name...the card, still pretty good. 4-mana is a steep price for creature removal, expecially non-exile effects, for standard play. However, Surveil 2 is pretty sweet and the legendary clause makes it great for dealing with some difficult legendary creatures. I could see this sideboarded in in place of Cast Down, if not just straight Maindecked as a 1 or 2-of.