The Google+ Developers group announced today that the next update to the +1 button is strictly a UI change, with no functionality differences. I like the look of the clicked button, after you have activated it by using the plus one functionality.
However, the +1 button itself, not clicked, seems a little too camouflaged to me. It blends in with the surrounding area and doesn’t yell “click me!” like a good “call to action” button should. We talk a lot about the difference between what good design looks like and good design that actually gets user interaction, so I’m sure the good folks developing the Google+ button have tested the new design and found that the new design outperforms the old. They wouldn’t just change things to keep changing things, would they?