I am a huge Apple fan and desperately sad to learn that its CEO Steve Jobs is unwell again and being treated for neuroendocrine cancer.

He has been widely credited with transforming Apple from a failing company in the 1990s to the very desirable and hugely successful brand it is today. The big question is, can it survive without him at the helm?

Such are the shock waves surrounding the health of Steve Jobs it was the page 1 lead story in yesterday’s Times. And the paper today reports that shares in Apple fell by nearly 6.5%, wiping nearly $20 billion off the company’s value.

However, I cannot believe that Apple has not thought this through after the previous serious ill health of Steve Jobs (pancreatic cancer and a liver transplant), and that a savvy creative heir apparent with a striking business acumen is not lined up. It must have been included in their business plan as a “threat”.

I’m sure Apple has a plan, but it is a very closed organization and may not declare its hand until it feels the time is right, and that probably depends on knowing how Steve Jobs’ health develops, whether he improves and will be fit to work again in the foreseeable future.

It certainly is a stark reminder about the dangers of having one man who is regarded as the brand, and as well as Apple, this includes Sir Richard Branson of Virgin, and Bill Gates of Microsoft.