Well, if there would be such an microATX Board any time soon (and *if* is the key word here), i would go for one of those simple mini towers, that have the same basic structure as your average Midi tower ATX case. two external 5,25" bays and one to two external 3,5" bay(s), since currently I need to have two CD/DVD drives. There are some variations on this kind of case available. E.g. most of the big ones like HP, Dell and so on ship their systems in such microATX cases. The one *I* would peronally really love to have is this one though: http://www.soldam.com/barebone/paradox/detail.html
(Not really an option due to it's price)
Currently I'm on a Mini ATX tower as well. It's the Suntek Bravo
(site is in german, sorry, but there are many pictures) - it's not really a good idea to go out and try building a silent system within such a mini tower (PSU mounted right on top of the CPU is not a good thing for overall airflow....), but I guess I'll stick with this (or maybe another nice Mini ATX tower, if I find one whose's size suits my needs) for a while, since there won't be a microATX board that would satisfy me I guess.
So If anyone out there has a good idea for a nice(!) ATX mini Tower that really is small (The Coolermaster ATC-500 e.g. should not be considered 'mini') or for a new 'high-end' microATX board with a nice tower..... I'll be here