It is the day before Apple's big event so I decided to put forward my predictions (wants) out for ridicule.
As I have no insider information, this is coming from me and only me. So take it with a grain of salt.
There will be a tablet, but more. The tablet will be a 10in 720p OLED tablet for reading books, magazines and newspapers, internet browser, media player (movies, tv, radio, music, podcasts, Audible) and will run all of the iPhone Apps, especially social networking type apps. It will be the same iPhone/Touch gaming platform for casual type games. It will have built-in Wifi (wireless N), Bluetooth and 3G for always on connectivity. Nothing new here that you may not have already heard about.
There will also be an Apple television (not the box, but an actual television) that will integrate with the tablet. You can be watching a show on the television, switch to the tablet to watch and back to the television seamlessly. Television will have built in wireless to run apps from the tablet. When watching on the television, the tablet is a universal remote with a slick touch interface to run the media on the television and other devices. The tablet is the ultimate computer in the living room.
In addition to the AppleTV Box or MacMini, you will have DVR capabilities.
Apple will be introducing a new ENTERTAINMENT platform that the tablet is just a part of.