In addition to Totem Expertise and Two-Handed Weapon Expertise, the other content tidbit from Heroes of the Feywild is that pixies will have a flying cap of 1 square. Reactions and interpretations are varied, with some stating that WotC should have waited for a better solution, and others expecting as such. Others are confused by what a height limitation of 1 square actually means, despite Rules Compendium explicitly stating that it means they can fly one square above the heads of Medium critters. As for myself, I was trying to make a pixie race for Liz because she played on in 3rd Edition, and am actually surprised that one of her balance pitches was exactly this (another was to impose an attack or defense penalty while hovering).
While I am reserving judgement until I actually see and use the final product, I think that being limited to one square off the ground is a pretty good deal; you get to ignore difficult terrain, hazardous terrain, and traps and hazards that trigger on the ground, but basically anything can still go after you in melee. Despite the aerial limitation, they can still fly well above the 1 square-ceiling, they just have to find a safe landing place before their turn ends to avoid falling. While this can make it handy to get to some hard to reach places, I cannot think of many situations where any other character could not do the same thing given another round or two, and a sufficiently high Athletics check. Now there might be more to it then just this, we will just have to wait and see.