As I said a few months back, I cannot recall when SO MANY major celebs/pop-culture icons died in the same year. Quite stunning, really.
It's only going to get exponentially more so as the years go by, so no, I'm not stunned.
Yes, as the population ages, particularly the much-heralded "baby boomers" who make up a large percentage thereof, we'll see more celebrities passing on. However I think Mike was also alluding to people dying before their time, such as Patrick Swayze, Michael Jackson, Natasha Richardson, and so forth. There were quite a number of those in '09 on top of those who lived full lives such as Karl Malden and so forth.
However, considering the fast lives that a number of celebs lived in the 60s, 70s, and 80s, they may start passing at a younger average age compared to the rest of the population. (I still think it's a miracle that Keith Richards is still alive. He must have the constitution of a bull.)