Quick question on tax deductions

So, the last post got me thinking about the interest deduction and I've been crunching some numbers to see if, with the mortgage and some major health expenses for Kate this spring, it might be worth itemizing this year. I don't have exact enough numbers on some of this stuff to know for sure (the medical one is kind of tricky), but it made me wonder... what percent of taxpayers actually itemize? It's something I never used to think about because my taxes were trivial to do, and then after college taxes got to be a little more of a chore but I wasn't close to having to worry about itemizing. That may change in the future (it may change this year depending on how this works out), but it really is a pretty big hurdle.

I only ask because I would have thought this percentage would be very easy to find, and I've been googling a little and it has been all that easy, which just made me more curious.