Weapon Block amount would be relative to item class (more sturdy the weapon, higher block amount) and should never match, much less exceed that, the block amount with a shield.
Moving on to the topic idea, though...
Strength should increase Block Amount (both Weapon and Shield style), as well as add to Armor (current)
Dex should increase Block Chance, as well as Dodge Chance (which it currently does)
Intelligence should increase Resistances (which it does) as well as reduce cooldowns on everything, including potions.
Vitality should increase Health (it does), as well as resource regeneration. The definition of Vitality typically includes "mental vigor" (per dictionary.com), so again this is only logical.
Implement the above changes, and loot will still have the same "boring" affixes (we didn't create any new ones), but those same affixes are now more useful, making loot better/less boring.... and we've come full circle.
Thoughts? Feedback? Other ideas?