While the idea of not having to split resources to develop two different desktop environment is welcome, I have my own reservations regarding this interesting development.
One important issue is the energy consumption. Unity-2D was a smarter choice when you are working on battery as it allows you to use your laptop for much longer period than Unity. I can’t quite tell if you are to blame Unity or Compiz for that but whichever it is, there should definitely be improvements on this part as considerable number of us use Ubuntu on our portable devices.
Also, Unity-2D has been way more responsive than Unity. While I can hope that the newer Unity versions improve on this matter, I was conveniently using Unity-2D until that actually happens. Now that the development on Unity-2D is going to be dropped, let’s just wish Unity stops being as resource intensive as it currently is.
That brings me to the next point. Accessibility has been broken in Unity for quite some time. I was quite happy that accessibility has not been neglected in Unity-2D, but since it has to go away now, I hope this no longer gives the Unity devs an excuse to neglect accessibility for one more cycle.
For all its worth, I hope the idea of dropping Unity-2D is given much thought and strongly discussed before anything actually happens. But, it seems we are well past that stage, leaving us with only one option: hope Unity can deliver.