I've seen the backpack too. Lots of room and it's got a kind of stiff form, foam padding like the breifcase to protect the laptop.
In my breifcase, I carry the laptop, all the cords (including the charger for my cell phone), a tracball, 30 CD/DVDcarrier, two removable drives, headphones, assorted pens and paper and usually a magazine or two. With plenty of room to spare.
If I want to take my laptop in a pack, I put it in a Threeday pack I have laying around. Less padding, but I already have it around. The laptop slides right into the back pocket which stablizes it.
John