I think Steve Wozniak nailed at least one thing in a recent interview when he was talking about Steve Jobs taking a leave of absence. Woz said that during an extended leave your mind has a chance to wander and think about things differently.
I wholeheartedly agree. In my life I've taken three major sabbaticals in my life since leaving college, and I highly recommend them.
In my first sabbatical I quit working in the aerospace industry after my first three years. I didn't like the places my Aerospace Engineering degree (from Texas A&M) were taking me, and I took a little time to re-consider where I was going. Since I didn't have much money, I mostly worked on painting the house and watching All My Children.
I finally decided to use, er, leverage my aero degree to work my way into the computer sciences world. My next job was working as a "computer guy" for an aerospace firm (working for Aerojet, who worked for Lockheed, who was working on the next generation rocket motors for the space shuttle).
That change was good for another five years, and eventually led me to my first $100K salary in 1995 at the age of 32.
But by this time I was very burned out, and very unhappy with my employer, who I tended to refer to as "The Evil Empire" after leaving. (I like to think I was right; they were out of business in three years.) They gave me a lot of opportunities, but I had to really work my butt off to get that $100K, and once again, I didn't like the direction my career was headed in. So I took some time off, and decided that I wanted to move from systems administration and programming into programming-only, and returned to work about six months later.
My last break came in 2007 when I sold the company I founded after my second sabbatical (Mission Data), packed up my belongings, and went to live in Alaska for what turned out to be one long summer (okay, one incredible summer). About three months into this break I felt fully recuperated and ready to get back to "work". Frankly, if one of my sisters was willing to open a restaurant I would have moved to Illinois and started that venture with her, but when she said no, I decided to come back to the computer programming world once again.
About Steve Jobs and his leave of absence
So, getting to Mr. Jobs -- and ignoring his health concerns and just thinking of this time as a sabbatical -- I have to imagine that this time off is going to do wonders for the man. Unencumbered by stress of "the daily grind", he's going to be free to explore and imagine, and I can't help but think that will do anything but good for him.
Now, it might not end up being great for Apple. One thing about a sabbatical, as I learned in my last one, is that you just might now come back. Mr. Jobs might decide that there are some really important on his Bucket List. But for Steve Jobs, human being, this might be a great time for his brain and creativity, and planning out his future.