The main difference will be speed.
The servers will be faster, the computers accessing will be faster, download speed will be faster and our access will be universal.
Because of the change in speed there will be more beautiful content. but the written is likely to survive because we can't photograph your hearts.
3D worlds will probably stop existing as such, rather they will be part of our total net experience. We will find news, work and play in second life...and second will connect to WoW and so on.
Access is the main thing. Take a dump in the toilet and it will recorded by your computer and emailed to your doctor (more likely your pacemaker might upload to your doctor, like cars can do now). You will get your toast in the morning and the weather report will be written on it (the technology already exists to do this).
But your wristwatch, phone, car, shoes, handbag will all connect to the net. We have special rooms and places just to avoid internet access. We won't see the net and our lives as different. We will have friend's living next door we have never met, and regularly go and visit our friend on the side of the world.
The most important thing is about control. This why TV is dying. I can choose the channel, but I might have to wait hours for the show I want. Online, I get what I want, and when I want it. Quality is not going to matter. Sure hollywood will post online at youtube, but a fuzzy out of focus camera shot of something news worthy will out rate it every time.
An interntet means a network of networks. The connection of everything. The Internet (big I not small i) is THE NETWORK OF NETWORKS. It will be everything and do everything.
We will have rooms devoted to the full on Internet experience and we will use tiny portable screens when that is needed. Mind control of computers will be possible, but how good it will be is another matter. Some people will unplug and disappear from the regular world. Unconnected, shopping with cash or battering their goods and labour.