Actually, Adobe Digital Editions seems to work fine with Wine on my computer - so why doesn't Adobe at least offer to Linux users the download of the Windows version? Look at Google, they even created some linux packages with their windows software, and use Wine, works at least. Here is an outdated version of Adobe Digital Editions, somebody has put this on the web: http://www.2shared.com/file/5072448/c47e1f1/digitaleditions.html
You can download standalone installable MS Windows version (it is available somewhere in download section). I have got it running under wine - even activated. But there is no support so if you can't access your library then you are on your own. Adobe did promise linux version some time ago (such info used to be in their FAQ) but now they will tell you they have no such plans. Personally I will keep downloading books without DRM (or with DRM removed). I did try to buy some books but it is a pain in *** and as my OS is not supported I will not support publishers. I hope they will kill DRM soon or later as it really is anti-customer crap - it is already happening with music ...