The tech world is abuzz this week over the news that, despite his open letter from last week stating that he was going to stay on the job, Steve Jobs has announced that he will be taking a six-month leave of absence from Apple.

For those of you who don’t know, Steve Jobs has been battling pancreatic cancer since 2004. He underwent a surgery called the Whipple procedure in which large portions of various intestinal organs are removed, and has appeared mostly healthy since then. However, throughout 2008 he was observed to be losing an alarming amount of weight, which as he described in last week’s letter, is not (directly) related to the cancer.

I’ve been reluctant to delve into this topic here, because I have a personal connection with pancreatic cancer. Someone close to me has been battling the disease since 2005, and in fact underwent the same surgical procedure as Jobs. It led to a remarkable recovery, allowing her to travel internationally in 2006 and 2007. She’s still with us, but it’s been a hard-fought battle against both the disease and the effects of chemotherapy. So, in short, I probably have a better idea than most observers of just what Jobs is up against.

His cancer may or may not have returned, and he may or may not return to Apple in June as he has promised. But regardless of his health, it’s true and obvious that eventually he’ll be leaving Apple, regardless of the reason. And despite his role as the company’s founder, prodigal son, and visionary leader for the past dozen years, Apple will go on without him. But a lot of people seem not to be able to imagine how.

Apple went on without him from 1985 to 1997. It struggled, yes, and was the butt of many jokes. But I became a loyal Apple user in the darkest of those dark days: 1993. I witnessed the foibles of Gil Amelio, and yet Apple managed to soldier on.

Then of course came the return of Jobs. The past decade since his return as CEO has seen the company vault from laughable also-ran in the computer business to an innovative leader, not just in computers but in portable music players and now smartphones (though that name does a disservice to the fact that the iPhone/iPod touch is really a brand new, pocket-sized computing platform that defies the currently available categories). Their computers are more popular than ever for home users, and they’re even making inroads into the business world.

And yet, Apple fans are still viewed as something of a cult. It’s a cult of personality, largely, focused squarely on Steven P. Jobs. So, what happens to the cult of Apple without His Eminence?

It’s true that Steve Jobs is a uniquely skilled CEO. He’s a visionary without peer, he’s a ruthless businessman, a shrewd leader, and a great showman. So who can fill that void?

Well, as it happens, Apple has some pretty impressive leadership in its other corner offices as well. I think the situation at Apple, and whether or not to be worried about Jobs leaving, is best expressed in pseudocode:

if (Cook + Schiller + Ive < Jobs) { panic; } else { do_not_panic; }

There are three people at Apple who really stand out from the crowd, besides Jobs himself. They are Tim Cook, the Chief Operating Officer, who was largely responsible for the outstanding success of the iTunes Store; Phil Schiller, the showman who more than adequately filled Jobs’ shoes at this year’s Macworld Expo keynote; and Jonathan Ive, the visionary designer who has been at the heart of just about every new product offering Apple has introduced since Jobs’ return and the world-changing original “gumdrop” iMac design.

In short… these are some brilliant, talented guys. What’s more, together the three of them are at least as responsible for the current state of Apple as is Jobs.

Apple is in good hands.