Android: 2D. OpenGl or android.graphics?
Now I've started to work with OpenGL ES, I would also use it for 2D graphics. This way is the most flexible and it's extremely fast (look at this example code. It's about 2D rendering, and there you can see the power of OpenGL.
It's not the easiest thing to start with, but there are some good tutorials out there - for example, this is a very good one.