Jeff C: Farhad is correct about the co-existence of the web and apps. The advantage of the web is that it has standards that can cross all operating systems. Even with the mish-mash of standards, developers can quickly build a website that can reach anybody. Apps have the advantage of a specialized interface for the task at hand. My bank's mobile banking page works great no matter what device I use.
As for always-on access and moving everything to the cloud, I think there is some overreach. For more than an hour each day I am disconnected from the mobile network. This is when I commute on the subway to work. What if my Kindle app required a constant connection to the net to function? There has to be an in-between—some local storage "cache" of my cloud files as well as cloud access. Otherwise my phone is a brick during my commute to and from work, not to mention for people living in rural areas.
Matthew: I, too, can see a future where we all work and live "in the cloud," but our network speeds will not be able to support this. Right now I have a few options for broadband access: Time Warner Cable and Windstream DSL, which both top out at about 10mbits/second, and Verizon 4G, which I believe tops out about 12mbits/second. I don't see those speeds getting better anytime soon. But the bigger problem will be the caps. As another person pointed out, AT&T caps iPhones at 250mb and makes you pay more for anything above that. The broadband providers will be the ones holding us back, and the barriers to entry are too high to have any real competition in the marketplace. Until that mess gets sorted out, I'll keep doing my work and storing my data locally.