Okay, I've been working on this for a while and I think that I have a good core system worked out.
Character generation:
It's based upon a few different factors. You first choose a Background - Barbarus (foreigner), Paganus (country-dweller) or Civilus (city-dweller). That determines your starting Attributes, Skills, Merits, the Races you can choose from and the Magic you start with. Barbarus is the only Background that allows you to play as a Canim or a Marat. Paganus starts out with more Physical Skills and more focused Magic, while Civilus starts out with access to more Merits, Mental Skills, and access to a more diverse array of Magic. Once you've got that picked you figure out your Race (if Barbarus), then move on to Attributes and Skills. Like While Wolf, you divide up your dots in these within limits that your Background provides.
After that you choose your Job. There are 16 Jobs to choose from - 4 Warriors, 4 Rogues, 4 Scholars, and 4 Others. The Warrior Jobs are Soldier, Knight, Scout and Duelist. The Rogue Jobs are Thief, Spy, Mask (master of disguise) and Assassin. The Scholar Jobs are Academic, Arcanist (specialist in ritual magic), Politician and Legion Officer. The Other jobs are Tradesman, Merchant, Performer and Farmhand. They each give you access to Feats, and allow you to pick up new dots in certain Skills/Attributes.
After that you choose your Magic. Paganus choose two 1st level and two 2nd level magics. Civilus choose four1st level magics. Barbarus choose one 1st level and one 2nd level magic from their race's special magic, and two other 1st level magics from either their special magic or Furycrafting.
Finally, you choose your Creed. Your Creed represents the core value or ethos that your character follows. Every time you make a heroic sacrifice or reach a milestone for your Creed, you get a Hero Point. Hero Points can be spent to do Magics you can't normally do, refresh your energy, or do other appropriately epic stuff.
Character growth:
You grow by earning xp. As you earn xp you pass certain thresholds, where your character effectively "levels up." These happen at 10 xp (Apprentice), 30 xp (Journeyman), 60 xp (Hero), 90 xp (Master), and 120 xp (Epic). You can also spend the xp you earn to get new abilities, though. Experience can be spent to buy levels in a new Job, to buy new Magics, to buy new Feats, or to Upgrade Magics you already know to make your character better at them.
Magics:
There is no "spell book" for the Codex Alera. Each character crafts their own powers within the mechanical and thematic guidelines given. Each higher level power builds on a lower level one, ranging from something like fury-assisted acrobatics at level 1 to flight at level 3 to epic feats of windcraft at level 5. Each power can also be upgraded, to make it more effective without raising its level. In this way, being better at one use of furycraft is distinguished from knowing many different uses of furycraft.
There are also 2 racial magics for each non-Aleran race. The Marat have Sun Chala (which makes their Chala stronger) and Moon Chala (which makes them stronger in the vein of their Chala). The Canim have Red Sorcery (curses that feed on Hit Points) and Green Sorcery (blessings that feed on Willpower).
The World:
The setting is 100 years post-First Lord's Fury. In that time the Alerans have expanded to retake most of their former land, and they have learned to live with their neighbors a bit better. The Academy Nova has been upgraded to the Collegium, and it now teaches soldiering, scholarship, politics, magic, and every other important discipline needed to maintain Alera. Kalare is still a smoking ruin, having been inhabited by the shattered remnants of the Vord. Rumblings of new troubles are on the horizon with the death of Gaius Tavarus Magnus, and the strange sights seen over the western horizon. Dead leviathans have started to wash ashore, and some have started to wonder if the Canean Vord are coming for Alera at last. Finally, the dead race called the Children of the Sun have returned to the Feverthorn Jungle, claiming to have been living in Maratea to avoid extermination at the hands of the Aleran Legions. It's a setting ripe for heroes.
There's still a whole lot left to do, but I have really enjoyed the effort and thought I'd share. I'm at the stage now where I'm playtesting the basics of the system with a few friends of mine. Unless somebody buys it (which I highly doubt) I'm never going to do anything commercial with it... but the idea has been burning up my mind for months, so I thought I might as well share my progress with you all.