Research prototypes exist today for such systems. An advertiser buys a 30 second commercial during the World Cup or Super Bowl, and at the next commercial break, you, along with 2 million other people attempt to access the same URLs. You want pages that contains both dynamically updating text and and embedded video window. Such prototypes exists today in commercial laboratories. When you reconnect, your system it should be able to re validate its cache, pick up notification of changes in the Web you are interested in, and potentially post forms you've filled out.
Many more examples are easy to generate.
One can argue that bandwidth and latency of the Internet will improve to wired locations. Both round trips and bandwidth usage must be minimized. Scaling issues are obviously already a major issue. The Web now is the heaviest user of bandwidth on the Internet. Solutions to some of the above examples will likely require use of multi-cast.