Instead of bumping the thread below from a year ago I wanted to ask roughly the same question a year later and see if the answers have changed. I'm slightly expanding the question from are there any mid-tower cases without 5.25" bays to are there any cases without 5.25" or 3.5" external bays. In the original thread, no one knew of a single mid-tower case without a 5.25" bay. Today, as far as I can tell, there is still no mid-tower case without 5.25" bays. If you expand the question out to include all cases this is what I have found but maybe I've missed something.
There are 16 cases without a 5.25" bay. Most of them are small format mITX cases and really there are only about 8 but some come in different colors. There are two cases that don't have 5.25" or 3.5" external bays. Both these cases are mITX boxes that will hold 6 3.5" or 2.5" drives and 19" video cards. So some progress has been made. It would be nice of bayless cases were offered across the many form factors of cases and not just in very small mITX cases.
So the question is, what is the point of a 5.25" external bay? I'm expanding that to include external 3.5" bays as well. Even if you have some reason for them, is that reason niche and easily solved some other way? Is your reason common enough that almost no cases are offered without these bays?
http://techreport.com/forums/viewtopic.php?f=16&t=78450