Looks like the last post supporting OD&D's use of d6 damage for all weapons seems to have struck a chord and even warranted a mention on the mighty Grognardia (a surprisingly large impact bearing in mind that I don't participate in any of the Old School forums and therefore lack any real promotional outlet for the blog). A few points were raised that are probably best answered in another post.
There's a glaring problem with d6-for-all in that it disadvantages the two handed weapon wielder. Why lose the single point of AC bonus for omitting a shield when your weapon will still only have the hurty-squealy potential of the short or broadsword that is accompanied by a shield?
Personally, I'm not too bothered about PCs not taking the two-handed weapon. For a start, they aren't really practical underground. A quick scan through the insanely complete weapons list for Tunnels and Trolls lists a few sizes for two-handed weapons;
Flamberge, Greatsword - 6'
Two-handed Broadsword - 5'
Spontoon - 8'
Bardiche - 9'
Billhook - 11'
Demi-lune - 12'
Partisan - 8'
These are not handy weapons underground. In fact they weren't handy weapons above ground on the mediaeval battleground unless they were wielded by bodies of men drilled to complement each other. Swinging an eleven foot long pole with a spiky bit on the head in the middle of a confused, underground melee in a rough tunnel is just asking for trouble.
Anyway, good luck sheltering under your greatsword or halberd when the arrow traps are going off left, right and centre and acid is dripping from the ceiling. You'll wish you had the shield then. :)
Magic Weapons i.e. Swords
Put simply, only Fighting Men can wield magic weapons. There are a number of reasons for this thusly
1 - The weapon's ego won't tolerate being inexpertly waved around in the general vicinity of the enemy by a weedy academic. They have their pride and need to respect the wielder - which means they won't work properly unless handled by a professional warrior
2 - It's fair to say that when the Gods create magic swords they do not do so with any old length of pig iron. Maximilllian the Magic-User's sword is an old hand-me-down shortsword with most of the rust polished off that Grandfather was forced to accept when he was conscripted into the Great War Against Whatever (before he deserted and went home to Grandmother). Flaybreath the Fighting-Man's sword is a proper job, heavier and with a greater reach and probably beyond Maximillian's skill to use safely - he'd probably lop his own ear off. Maximillian trying to use the sort of pointy length of tempered steel (rolled on the naked thighs of Immortal Vestal Virgins) that Flaybreath dreams of being handed down to him by the Gods on the slopes of their holy mountain would be akin to giving him a Ferrari to go to the shops with when he'd be much better off with a Ford Fiesta. Maximillian should be frightened of any decent-looking sword.
3 - Demons in the sword argue with the demons in the Magic-Users head and start sulking and then don't work. (The DM's hand-waving excuse).
Following the comments on here and Grognardia, I am seriously tempted by the idea of damage, not by weapon, but by class. That's a wee bit similar to the idea in Tunnels and Trolls where Warriors rate their armour as double that of any non-Warrior wearing the same armour because they know how to use it to turn blows.