I just have to laugh at all those who claim tablets are dead, windows has proven it`s a non-starter, etc etc.
Apple has proven it can build a highly usable & successful tablet platform, they've already sold 30 million of them as of the end of 2008.
Question is whether it`ll have a physical keyboard either attached or as an optional accessory.
I think from the bullishness of Apple regarding it`s multi touch on-screen keyboards and the fact that building a dozen or so keyboard variants for a device they aren`t completely sure they`ll flog millions of mean it`ll probably not include one as standard.
I could envisage Apple leaving this to the 3rd party market. Release the tablet with a bluetooth HID profile or a keyboard protocol offered via the ipod dock connector. Then you`ll have a dozen manufacturers building keyboards and cases with inbuilt keyboards. The fittest design will win out and Apple doesn`t have to risk/spend any money to do it.
My personal design favourite would be a case that hinges down the longest side to reveal a wired keyboard with an inbuilt battery for longer trips away from the power socket.
M.