I'm fairly sure that the Casale CPM rate varies with your traffic type, but it tends to be on the higher end of the spectrum, although they usually don't fill all of your available impressions. I've heard eCPM's in the $0.40's to $0.70's and sometimes more.
From all the forums I've been visiting it seems pretty concrete its about $0.45 + per 1000 impressions. This does vary again with the type of site niche you have, but on average those are the rates to expect.