Though this pertains more to photography (though adaptable for DV), I’ve had some great experiences with the Lowepro CompuDaypack that I took with me to Europe. This bag is designed to hold both a laptop and camera, and it saved my equipment in more than one way.
First, there’s the obvious padded protection that any decent photo bag offers. The bottom section is your typical, top loading compartmentalized camera section, with enough room for my Nikon D80, Yashica 12 TLR, and some charging accessories. The upper part has a bunch of pockets, two water tight pouches for memory cards, and enough room for a book and some souvenirs. Running the height of the bag is a fully padded laptop compartment and pocket to store papers and magazines.
My other photo backpack, a more dated version of the Lowepro Rover, seems to be more roomier and a bit more padded, but the CompuDaypack held everything just fine. I’d consider the Daypack more urban while the Rover, with a waist strap and ties, is better for the outdoors and hiking.
In Europe, it rained just about everyday, sometimes leaving us soaked. This is another way the bag saved the equipment. While at the end of the day my friend and I were drenched, the protective material of the bag kept everything dry and safe.
Finally, in Prague, we parked the car down a side street many blocks away from our hostel. It was too far a walk to carry my large suitcase, but I easily took my backpack with me. That night, our car was broken into and my bag and my friend’s bags, which contained his laptop and backup hard drive, were stolen. Fortunately, my most valuable possessions (including Harry Potter 7) were with me because of this bag (finding replacements for my prescription medicine in Vienna is another story).
While it’s designed for photo equipment, I’m sure if all the dividing padding is removed you could fit a DVX100 or GL2 in the bottom, with a MacBook Pro in the back for a completely mobile workstation.
Best of all, the bag is only $50 at Amazon. Small price for some excellent security and mobility.