Adobe to Require New Epub DRM in July, Expects to Abandon Existing Users
The tl;dr version is that Adobe is going to start pushing for ebook vendors to provide support for the new DRM in March, and when July rolls Adobe is going to force the ebook vendors to stop supporting the older DRM. (Hadrien Gardeur, Paul Durrant, and Martyn Daniels concur on this interpretation.)
This means that any app or device which still uses the older Adobe DRM will be cut off. Luckily for many users, that penalty probably will not affect readers who use Kobo or Google reading apps or devices; to the best of my knowledge neither uses the Adobe DRM internally. And of course Kindle and Apple customers won’t even notice, thanks to those companies’ wise decision to use their own DRM.