Short answer: No.
No, because there will always be a hobbiest element to computing, and you can’t be an iPad hobbiest. Seriously, that internet appliance is so locked down, I’m surprised that it doesn’t have a chain connecting it to Apple headquarters in Cupertino. Oh, it does; it’s called iTunes and the app store.
Tablets (I’m talking about the iPad here) are new and shiny, but you still need a PC (running Windows) or Mac to initialize them with iTunes. I’m not sure about the Android powered ones, but I’m sure you need to connect them to your computer to move files over and whatnot. So you still need a traditional computer, whether that’s a laptop or a desktop.
I will hold onto my laptop and netbook for awhile. I doubt a tablet would work for me.
I never really saw how I could do stuff like spreadsheets/wordprocessing on a tablet, but I can see doing artwork on one. It’s really hard to work with the Gimp and a mouse, but creating art with a tablet device would be very cool.
I guess my issue with the current round of tablets is that they’re just appliances for media consumption. You can’t customize them, you can’t control what you get through filters/extensions and whatnot on the browser… and it seems like you need to get an “app” to access various parts of the web. And those “app” coders can serve advertisements and you have no control over whether you see them or not. That’s a serious problem for me; I will not allow a website free reign over my computer to serve ads to me. It’s one of the reasons why I use an adblocker. I’m not opposed to some ads; the google text ones aren’t bad. I’ll also pay for content and services (see: This is True, deviantART, pinboard) that I support.
Anyway, I hate it when people claim something is dead. Physical media, TV, radio, newspapers, books, pencil and paper, and playing cards are all decidedly not dead. I use them every day.