Hey, I just fixed my Finder draining the CPU, but not quite with the fix mentioned above - it certainly helped get me there though - thank you.
What I did was go to a Finder Window showing my user folders (when viewed as List) and went to "Show View Options" and un-checked "Calculate All Sizes".
...it worked! ...but I investigated further and opened up Activity Monitor, re-checked the Show View Options, as expected CPU on Finder went up to 97-105%, so I went to my Finder Window and moved to my Documents (from the sidebar menu; when viewed as List) - the CPU went right down!
Is Finder getting stuck in a loop? ...just opened up the Library folder (again in List view) and there - somewhere, lies the problem; I think finder is always working to calculate a size of an Invisible file.
Anyone else have the same problem? ...can Apple fix this?
This was the source of my problem too. I had turned on "Calculate All Sizes" a few weeks back, and lately every once in a while, the Finder would get stuck at 100% CPU usage, and wouldn't go away unless i rebooted. Turning off "Calculate All Sizes" fixed the problem.