Fallout 3 Forum Tidbits

Lead designer Emil Pagliarulo talks about combat in Fallout 3 on the Bethesda Game Studios Forum.
It's basically what Pete said, as quoted above.

For us, balancing the combat is very much a "feel" thing. It's something that takes a ton of playtesting (involving the entire dev team), and determining what feels right for everyone. It's all about finding that nebulous perfect balance between player skill and character skill.

In run-and-gun, melee feels a lot like melee in Oblivion. If you connect with the weapon, you hit. There's no die roll to determine that. But your character's skill, as well as the condition of the weapon, determine the damage done.

In run-and-gun, ranged combat is... I dunno. I'd say it feels a lot like Deus Ex 1. Accuracy is affected by player skill and weapon condition -- so if you've got, say, a really high Small Guns skill and a perfect condition assault rifle, your aim will be dead on. Low Small Guns and crappy assault rifle, and you'll miss more. The skill and condition also affect the damage you'll do.

With most ranged weapons in run-and-gun, you can also go into an aim mode, which zooms you in and increases your accuracy. With Melee and Unarmed weapons, the player will block instead of zooming in.

Based on all the feedback we've gotten, it feels really solid now.

Of course, V.A.T.S. is its own story completely...

I'd say for combat, I generally go 70% V.A.T.S., 30% run-and-gun (but that's different for everyone, really).
In another post, he talks about the nature of armor in Fallout 3.
I know it's been mentioned in some preview or other that all the apparel (armor and clothing) is a single suit. Headgear is separate. There are a LOT of apparel options, and yes, there are are some pieces of clothing that give stat boosts, so if you decide to wear clothing and not armor, you'll still get a discernible gameplay benefit.

I've seen some apparel/headgear combinations I never would have imagined (some which involve a big pre-war lady's sunhat...)