I think it’s a combination of network speed and the CPU that contributes to slow browsing on mobile phones. Have you ever used a laptop tethered to a 3G cell phone? Yeah, not so fast.
I don’t think traditional browsers or computers will be obsolete for many years. I don’t believe the way we interact with computers will change that much either, at least not for a very long time. This isn’t for technical reasons, but human reasons. Many people have a hard enough time dealing with computers as they are now and most people don’t adapt to change well. There is still going to be screens, text on screens, graphics, keyboard, mice, etc for quite a while in my opinion. Sure touch screens were supposed to change how we used computers but tablet PCs never really caught on in a mass-market way. The iPhone and other touch screen phone/computers is the closest to that reality, but I still don’t really think that’s a major shift from clicking a mouse instead of touching a screen. Touch screen desktops are a horrible idea in every incarnation I’ve seen so far. I don’t want to wave my arms around out in front of me for 8 hours a day and have smudges all over my screen.
If anything people are starting to be satisfied with the speed of computers and their abilities now. Take netbooks for example. People are buying them like hot cakes because of their low price, despite the small size and very low performance or whizbang features. There is of course a subset of people like gamers that are always looking for the next performance boost, but for many people the computer is now as fast as it needs to be for them to accomplish all the tasks they need to do. That’s not to say I don’t think computers will always continue to improve in speed, they will. But right now I don’t think it’s as important for most people’s needs. Virtual reality and embedded computers and all that type of stuff are a long ways off for practical usage. Even talking to your computer rather than typing is still far from perfect and I for one would rather type than talk to my computer, especially in public places. If anything I think the desktop computer will start to serve as more of a server, as more and more devices are networkable and able to connect to the internet such as game consoles, portable devices, media centers, home control systems, etc. Traditional computers and desktop browsers are going to be around for quite a while. But what do I know, I’m just a guy on the internet. :)