Shorter development cycles? Are you kidding? The shorter the better. Even if the changes are few, someone might be just waiting for that new feature (like me waiting for dxf export). If you can handle the extra work - please release as often as possible. This will keep people interested - hey look the site is alive and kicking.
Maybe you can use the philosophy of stable and unstable branches. You could offer more than one version to save the file in, a stable or old and a unstable or test version. The test version would be the one with the extra information in the header or somewhere about who built it in what environment. Maybe you could ad a notes section to the file. If I have issues with a certain file one could add some descriptive info. (Like this file wont load into version soandso). The normal file version may not need this and could save the space.
I spent some time on the Trackdraw project at
http://www.trackdraw.org and learned that new versions often broke things that had worked before (svg export seemed always to be critical). Yet a live forum and frequent releases seemed the best way to solve problems.
Addressing the start of this thread maybe a roadmap such as here
http://dark-oberon.sourceforge.net/?page=roadmap might be usefull. It may give the interested user an idea of what is happening and were you plan to go when.
I know nothing of the legal base or the infrastructure behind this project but if is to become an open source comunity effort I would suggest you release more information on how others can contribute. This way you may have more to add in shorter releases. A suggestions section for plugins and some howto might be a start as well as letting others start some translating. Localization or i18n has proven vital to the spread of other projects. It does open more doors into local schoolrooms. I did write an html formular that used javascript to help translate and generate the proper xml files for the language based strings in Trackdraw. It showed that storing translatable strings in easily editable extern files was very usefull.
I had requested a loader or wrapper for the portableapps.com menu here
http://portableapps.com/node/11172 maybe you could help with an in between version suited for portability or at least document where Cademia stores what information or even host a special portable usb key friendly version on your own site.
Maybe the plugins at
http://www.litecad.com/ could be usefull?
Oh somewhat offtopic but have you read the entry about Cademia here?
http://de.wikipedia.org/wiki/Diskussion:Liste_mechanischer_CAD-Programme#CADemia There's quite a lot of issues addressed there

As it seems you might want to investigate the possabilities of skins for the GUI. A CAD-profi version like you already have, a grafic-design guy version with a maximum of mouse input, a schoolboy version with lots of icons and a gardeners version with a plant library... oh well halfway kidding... nevertheless skins are cool.
maybe next time I should split my posts...
und tschuess
t.woelk