Yeah, swords are light.
Thing I am concerned about is kinda close, but different. In Oblivion swords were MUCH lighter than comparable axes-maces. Which is wrong. Axes and maces are not particularily heavier than swords in general. There is no point to use anything but swords in Obilvion, except for, well, RP stuff / personal artistic preference / et cetera.
I know that in Skyrim weapons will be quite a bit different due to perks, but if Average McSword will weigh 10 units of weight, and Average McMace will weigh 15 units of weight, while providing comparable damage, well, it would make no sense to specialize in maces. Sure, armor crushing stuff, yeah, perks, cool savage looks, all that stuff. It still will svck.
I, for example, would be happy to play as a Spellaxe, but if axe will be way heavier than sword, then I'll just say "meh, my Breton is too weak to carry this unnaturaly heavy piece of wood with kinda small metal head attached, he would be better to use lighter weapon completely made from metal". And when I'll play some Nord warrior for kicks, I'll cover him in Heavy Armor from start and then will compare Two-Handed Fantasy Sledgehammer aka Warhammer, weight 60, and a Claymore, weight 30. Then I'll say "meh, I still need some encumbrance for loot".
Weapons are light. In general.
About these oversized swords someone states to own. I have a two-handed sword, made of steel, tested in training combat. Unsharpened, of course. It weighs 3,4 kg. It is not very large, about 150 cm maybe. I can imagine that larger swords, close to 180 or even more than that, can reach weight up to 4 kg, even 4,5, while still being battle-ready. Maybe, though I am not sure of that, 5 kg.
Several years ago I was in theatre, behind the curtains — friends worked there. Among other things, play requisite included a giant two-handed "sword". It just stands there, at the back of the scene, looking good and large enough to be noticed by people from back rows. Nobody ever uses this prop for anything resembling a fight. It weighs 12 kg. I tried to swing it. Yes, it is possible, but just once. Inertia is too great, it is impossible to
fight with this thing. If I had a dagger (or was unarmed) and my enemy tried to attack me with weapon this heavy, I'd just evaded his terrible blow and charged ahead into close combat, where his "sword" is useless.
Another thing I hope Bethesda takes into account is European style swords where not meant to be used as slashing weapons, but for thrusting (hence the strait blade). Swords such as sabers, scimitars, and the katana where meant to slash.
Not exactly true. Sure, european straight swords are better suited for thrusting than, say, japanese curved swords, but they are definitely were made for slashing (or chopping, which is more accurate). Just check out Oakeshott's classification — you will see how sword changed from viking-style choppa to rapier-looking swords. This transition went on for a several centuries.
More than that, there were swords designed only to thrust: estocks and rapiers. They either had no cutting edge (former) or were too thin and light to deliver a good chop (some of the latter).
Emphasis on thrust was necessary due to advances in armorsmithing. Then it just became a habit, even after armor became obsolete because of firearms advances. Though curved cutting swords were used on European battlefields up at least 1920-s, and Japanese used their curved cutting swords in WW2.