From what I remember (from what I believe was posted in the "too lazy to make a thread" thread) weapons become better than shields for blocking over time as your skill with them increases.
I don't know exact numbers though, i'll go dig through that thread.
EDIT: Found it, but still no exact numbers. Could've sworn there were though...
Ischaldirh wrote
As the game is balanced currently it's generally accepted that two weapons are the best way to go.
Which was in response to:
Azhael wrote
Another question, what do you consider that is better: wielding two weapons or a weapon and a shield? I have a valpurium two handed sword+6, a valpurium shield and a flaming ruby sword+6, and I seem to do quite well with the two swords as I block many attacks and have two strikes in one turn... but I would like to know if having a high skill with the shield will make me almost untouchable and would be better that way. Right now my char has 41 dex and 24 agi.