I carry a Targus. Other than the fact that it has a cell phone holder on the strap (which I may remove), it doesn't scream "Laptop bag". This old guy in Canton asked me "You going campin' son?". Yup. I always go camping in slacks and a dress shirt.
I think it's great that backpacks are now the norm for carrying laptops, papers, etc. I've been doing it for a few years, and I used to get a few comments on how it's "unprofessional". Not anymore. I carry mine in a suit. Conventional laptop bags? Pfft. They're extremely uncomfortable, and if you ask me, you look more squared away with a nice looking backpack over your shoulder. It used to be that I only saw young tech professionals like myself carrying them. Now, I'm seeing regular guys in their mid forties using them. Progress is good.
I declare the breifcase dead.
Know the other neat part? It's a great place to carry quite the assortment of fine defensive weapons, or at least tons of spare ammo and mags. Making them accessible is also quite easy - certainly easier than reaching under my tucked-in shirt while at work (though one should always keep one on their person). All it takes is a little creativity and good judgement when buying your backpack.