With Android Studio 1.0 release, ADT is deprecated
It is time for everyone to migrate to Studio. From the Tools website:
If you have been using Eclipse with ADT, be aware that Android Studio is now the official IDE for Android, so you should migrate to Android Studio in order to continue to receive all the latest IDE updates. For help moving projects, see Migrating to Android Studio.
Basically, they have been saying this for a year, and now it is in print.