If they held a big event to introduce these new models -- or just about any other product -- the headline would be the absence of Steve Jobs, which is probably not what Apple's PR department is hoping for right now. If they bring out a tablet PC or something equally dramatic, they might want to risk that, with the spin 'Even without Jobs we can still generate excitement.' But for ordinary improvements to the existing hardware line, a big Jobsless presentation would be a negative, on balance.