The Peak Oil folks.
The tree huggers.
The gentleman who wrote the article linked to below.
Various intelligent people (Rogers, Leeb, Simmons, Deffeyes, et al).
Oil is a finite resource.
It is and has been cheap.
Because it was cheap, people didn't appreciate it properly.
Now that the cheap oil is getting scarce, what's left is getting expensive.
As it gets expensive, people will learn to appreciate it properly.
We should probably have priced oil higher all along to avoid this problem (as the Europeans did), but we were shortsighted.
If you are smart, you are adjusting your lifestyle to reduce your exposure to energy prices now.
In the end, the solution is $100 oil.
PS. We all agree that oil is going higher, we don't necessarily agree on when and how much, nor on what happens next.