"I have found what you see on the computer monitor noise wise, doesn't show up in print nearly as bad "

That has been my experience as well. Prints at 1600 with my 40d were very usable for weddings, etc. I just used the 5d ii (as the 2nd body to my 40d) at my first wedding this weekend and wound up taking some shots at ISO 6400. Much of my work was taken at 3200. We shall see how those come out.

James