I'd like to know where some of you are getting your cooling info. It surely isn't from experience. Using 10, 20, or 50 fans (I know it is an exageration but..) this is rediculuous. The more fans you add, the more difficult it is to control the airflow without creating "dead air", which are places where air gets trapped because of the turbulence of all the fans blowing in different directions. I've seen many cases that have several fans, in the side panel alone, but, while they look cool, they don't do anything other than hinder the airflow inside the case. If you have a fan in a side panel sucking air out, and it is directly over the CPU fan, it is hindering the CPU fan because the CPU fan is trying to blow air that the other fan is trying to pull away from it. If one of these fans is stron enough, it could stop the other, or at least slow it down and eventually burn it up. There are correct ways of venting and ducting when using that many fans but it is not necessary if you can acomplish your goal in another way. The most important thing is to move the hot air out and cool air in, which I have tried many times to stress but it seems to be ignored.
Someone said to remove the cover to increase airflow, this is wrong and will kill any airflow except that of the fans. Areas with no fans will be in dead air. If you remove the cover, you better get a house fan or you're asking for trouble.
The most intelligent reply I've seen was made by Rick when he explained the effects of heat on the drives. Similar things happen to the solid state components in the system as well. When they get hot and cold, the substrate becomes less stable. This shortens their life.