Maybe part of what we'll get by choosing a faction will be something that makes certain shard types more valuable than others, but I'm starting to suspect that there might not be anything like choosing to be an 'element' specialist, a dualist, or a generalist. If my suspicion turns out to be accurate, I'll be a bit disappointed, but explaining why would lead me to discussing the Unmentionable Predecessor...
heh.
I don't really see it as a problem. Picking magic books/schools/spheres/whatever gives you the options to specialize at the start of a game. But since mana of a given type only comes from shards of that type, if the shards aren't terribly common, what you can get access to in game provides the same type of limitations based on the map and what you can control.
I kind of like that dynamic. If I want to cast fire spells, I need to get ahold of a fire shard. Its a change from say the AoW:SM dynamic, where if I want to cast fire spells I pick fire spheres, then I can cast fire spells even if all I control is water nodes.