The consensus, such as it is, comes down to three possibilities:
1. Apple is playing hardball with IDC, the conference organiser, to get some kind of reduction in next year's fee.
2. There aren't going to be any revolutionary new products and so Steve can't be bothered to show.
3. Jobs' health has deteriorated so much that he can't manage to do it.
It's the third option that is most worrisome for Apple executives, and the share price is looking jittery.
Of course, if Jobs had followed Bill Gates' lead and obviously groomed a successor like Steve Ballmer this wouldn't be an issue. But Jobs is quite happy being Mr Apple and, some have said, remains paranoid about being pushed out of the company a second time.
Whatever the reason it's clear the Apple board is going to have to have a sit down with him and sort this out because it's not good for the company. Analysts estimate Apple stock could take a 20 per cent hit if Jobs pops his clogs.
Microsoft seizes control of phishing sites linked with Russian state hackers
Fitness trackers over-estimate the number of steps their users take, analysis of 67 research reports suggests
Everything we think we know about the imminent Apple iPhone 9, iPhone 11 and iPhone 11 Plus launches
All the latest rumours about Apple iPhone Displays, CPUs, launch dates and even prices
Nvidia brings Turing microarchitecture into the high-end gaming segment