there is precedent for new product announcements at a keynote without steve, although he had cancer at the time - fingers crossed (for a new announcement, not SJ to have further ill health).
I appreciate that all companies have to promote themselves and that means a fair amount of exageration when it comes to forthcoming products but it is furstrating when you know that the components exist. In the pc world once intel have a new chip it'll be shipping in a computer. To apple's credit their less frequent updates make product lines easier to follow. I have been looking at pc laptops on behalf of my little brother - very confusing, not sure whether one set up will run that differently to anything else and because manufacturers have so many different configs finding a review of teh exact system that you are interested in is almost impossible. I tried to convert him to macs but he wasn't having any of it - plus it is difficult to in good conscience suggest an apple laptop over a pc at present given the bag for buck involved.