Maybe weapon rebalance, but I hope that it won't be necessary. Anyway, if it would be necessary, basic idea is to make each weapon type good in some way, to destroy, say, Oblivion way of Dagger < Short Sword < Long Sword. Short Sword is shorter, and it packs less damage per hit, but it should be way faster and probably deal more damage per second, being viable choice. That sort of stuff. Oh, and similar approach to materials, so that some would be heavier and stronger, but less enchantable, et cetera.
Again, hope that it won't be necessary.
I did that for both weapons and armor in Morrowind, but that was only a bit of tweaking here and there (for instance, made adamantium less durable than bonemold, made netch leather more durable than chitin, made dreugh lighter and a bit weaker and upped its enchantment value.... that sort of thing). I've long threatened to do the same thing with Oblivion, but haven't done much just because doing it right would require redoing just about everything. So pretty much all I've done there is fixes - changed the reach and speed of the Akaviri dai-katana (which are both the same as a longsword by default), lowered the weight of the silver claymore (by default weighs exactly the same as the dwarven), fixed the reach and speed on the elven war axes, stuff like that.
As you say, I hope that it won't be necessary in Skyrim, but I suspect that it will. If so, I hope that at least it's akin to Morrowind and I'll be able to just tweak things here and there rather than having to overhaul everything. Or maybe more accurately, promise myself that someday I'm going to get around to overhauling everything.....