These are some great suggestions, folks - thank you! Some real inspiration here.

I really like the Briggs & Riley but does it not have a shoulder strap? I think that would be even more important than a pass-through sleeve on the back... so much so I didn't even mention it as a 'must have.' Oops.

The Waterfield Designs bag looks great, too - I don't mind THAT type of messenger bag flap. I just don't want to flap the whole thing open to get one thing out of the bag... but the separate flap compartment? That's just great.

The Everki backpacks look very nice (and I'm not one of those "Oh no! A backpack won't look so nice in a professional setting!" guys...) but the briefcase has the split handle thing that I dislike so much.

So many options...