I've been checking out the Bioware forums. Concensus seems to be that:
1. Warriors should focus on Dex, and only do the minimum they need to Strength.
2. Rogues should do minumum they need to Dex (34, probably), then focus on Cunning.
--This may or may not lead to lower unit dps, but it is definitely much better party dps due to awesome Song of Courage buffs.
--Things get really iffy when it comes to Awakening, but it looks like Dex might be better there (I'm guessing because of accuracy issues, but no one elaborates).
--I see some allusions to console glitches, but no one elaborates.
3. Optimal DPS by a huge margin comes from a build using Repeaters Gloves or Rock Mastery, Aim, and Master Archer with no additional talents. Due to the animation time of abilities, they do vastly lower damage over time compared to simply auto-attacking. Of course, you might choose to sacrifice dps for utility.
4. I have seen it mentioned elsewhere that a hotfix patch broke shortbows to only factor in Dexterity. But literally all of the best bows in the game are longbows, and you should almost definitely have one of them by the time you can get lethality, so it shouldn't be an issue. Plus, shortbows actually suck. A lot. You can very easily reduce your aim time to 0 with a longbow, which makes their faster speed irrelevant, so you end up with a lower damage bow with lower ArP firing at the same rate at a shorter range.
I think it's safe to say that, if using a Longbow, it's 50/50 Strength and Dexterity. Still doesn't tell which is the better build (and if you aren't using the Bard spec, that's really up to you. Though I don't know why you'd pass up Song of Courage--Assassin is useless for Archers and you don't want to be in melee range to take advantage of Duelist). This post feels somewhat reliable.