Hi Wallcraft,
Both our Android apps and iphone apps will read any unencrypted ePubs. This functionality is not on our Desktop application yet, but it will be coming soon (not enough hours in the day!
). Same with the Kobo eReader, you can drag and drop any unencrypted ePub onto it and it will read it.
For encrypted content from 3rd parties, it's a bit different. Right now only the Kobo eReader supports Adobe DRM'd content, and we're looking into enabling support for Adobe DRM on our other platforms.
Hope that clarifies.
Gbloom182,
If you get a Kobo eReader, you should be able to authorize and load DRMed ePub files onto it through Adobe Digital Editions as long as you have not run out activations (It allows 6 devices per ID as Wallcraft has pointed out).
Hope that helps in your purchase decision. Good news is that regardless of which of those devices you choose, you will have access to all the content and deals from kobo.com.