There are a couple cards I'm considering with the addition of M14 to the Standard landscape (listed in alphabetical order, not order if priority).
Archangel of Thune - I probably don't have the right deck for this since there's not a lot of lifegain going on. Still, it's something to consider, I suppose.
Celestial Flare - Some of my toughest matchups are against the hexproof decks, which might become even harder now that Witchstalker and Gladecover Scout are in the format. Celestial Flare seems to be well-positioned to combat the "all-in, pants-on" kind of enchantment decks.
Chandra, Pyromaster - Card advantage...sorta. But probably not the best fit in this kind of deck. Still worth trying out, I think.
Fiendslayer Paladin - Semi pro-black/red seems decent. At least from the sideboard.
Flames of the Firebrand - I'll consider this more when rotation hits and I loose Bonfire of the Damned and Searing Spear. I still might prefer Clan Defiance or Aurelia's Fury over it though.
Garruk, Caller of Beasts - Once Garruk, Primal Hunter leaves, I'll probably like him more. I like Big-Naya over pure-aggro, which is why I've kept the more midrange-y cards. And Caller of Beasts seems like a decent addition. At least in the sideboard.
Kalonian Hydra - I'm not running Exava, Rakdos Bloodwitch, so I don't quite have the optimal build for this. But it's a powerful 5-drop nonetheless.
Kalonian Tusker - the GG cost might be a bit too hard to do in this deck (on turn 2). Since I'm not all-in Aggro, I think I can live without him.
Ogre Battledriver - I REALLY like this card. I think it can do a lot for this deck. Definitely going to test him out.
Primeval Bounty - I think this is more a build-around type of card, but it's essentially a planeswalker. But with the announcement that Theros will be more "enchantment-matters" I suspect we'll see more enchantment-hate floating around. And I don't really want to spend 6 mana only to lose my right away. Still, I really like what this does.
Savage Summoning - Something to consider when Cavern of Souls rotates, but I'm not sure I'm running the right deck for it.
Scavenging Ooze - I really like this guy, and I've got a whole load of the promos...We'll see if this is the right place for him.
Shock - Burn, but only when better things rotate.
Silence - Maybe...
Witchstalker - Depends on where the meta goes. But I've already loaded up on 3-drops.