From the "Player's" section of the Charter:
Every time your character gains a level, you can retrain one feat, power, and skill. If new character options have been approved for play in L4W since your character’s last approval of submission or level-up, you may additionally retrain one new feat, power, and class feature (when selectable) from the new source(s).
So, yeah, you guys are right, since MP is new since we all leveled up last, we get one free retraining if we're using something from MP beyond the normal one. So, actually, Hrav can retrain something normally at level 3, another thing at level 4, and another thing if it's new since he hit level 2. Not sure I'll do all that, but I'll have to look to see if there's anything from MP, PHB2, or Dragon I want while I'm strategizing. Our "new material" rule had slipped my mind.
And I agree with Ata, Distant Flanking should be really helpful for Girth, especially if we go back up to having 4 melee characters.
EDIT: Just realized that the Charter even says (in italics, even!) that you can retrain one fear, power, AND skill. I don't remember deciding that.

Still, that much more flexibility.