Ken did a very detailed study on coffee freezing on Home-Barista.
Coffee: To freeze or Not to Freeze with some surprising results. There is also a thread floating around on the subject where stated my observations. My opinion, freezing freshly roasted beans does no harm provided they are frozen properly. However, the freezing process does not stop out gassing, it only slows it so use it all up in 3 months. Freeing greens is another subject all together. I vac pack and deep freeze all my greens; they will keep much better that way.