I've been shooting a 60D since April and recently got into stock photography. However, many of my files were getting rejected due to noise. (Even at ISO 100) Needless to say it's a little insulting when they reject a file and tell you "how you should have shot it." (Even though I was already shooting at ISO 100)
Anyway, I recently purchased a 5DmkI and for the first time have noise free shadows and clean sky. My 5D's ISO 400 is my 60D's 100.
I haven't yet had a file rejected due to noise from my 5D.
Survey says that the 60D is a bit noisy. For everyday photography photography or making small to medium prints it's not a big deal. However, when you have inspectors scrutinizing your photos at 100 percent, the 60D is going to leave you hanging.