I think that this 8 Gig USB drive is a great idea. I would love to see the day when I can carry all of my personal files around with me everywhere I go. When I can have all of my data with me at school, work, home, or wherever I go, I will be a happy camper. I know this isn't the only way we can achieve this goal...you could easily carry everything on the hard drive of your iPod and services exist to allow access to your home PC over the internet...but they aren't as convenient as a USB drive! Even taking your laptop everywhere isn't as convenient as carrying everything in your pocket!
I already carry a USB drive, but my 512 MB unit is not enough for all of my data and I find myself having to judiciously decide what resides on it. Eight gigs is a really good step in the right direction though! That's enough space to carry all of my documents and a pretty good collection of multimedia content as well.
Sure, there are more than a couple of problems like loss, theft, security and other concerns, but I personally think we will see the portable media storage market grow stronger over time. Time will be the real test.