I am really interested to know how auto-attack will effect GLA's Guard ability, especially in light of the change to Ambidexterity.

Ambidexterity will increase the chance of blocks while guarding, instead of halving the stamina gauge cost of your next action.
I would have posted this in the existing thread (and I actually did) about the auto-attack changes, but its been overrun by disgruntled archers. Also I am kinda suprised more GLAs werent interested in what auto-attack means for shield usage in general.

For instance will we keep the current system intact, but use cooldowns instead of stamina, or will Guard become random like parry and evade, or will it be more like a stance or a mode?

Also by how much will Ambidexterity increase your block %, and will it make lower block rate shields more viable? Like a trade off: get a Decorated Iron Scutum and use Self-Preservation VS. using a Raptorskin Targe with Ambidexterity.

I'd really love to get a dev comment on this issue, but the floor is definately up for speculators too. And yes I realize that they probably would have mentioned a change in the way Guard works, but I would feel better with clarification.