UPDATE: July 1, 2013
Just like Yahoo! MediaPlayer, this plugin has also mysteriously disappeared. However, you can get something just like it (better, IMHO), called PressPlay Lite, which is now available on WordPress.org.
Not shown. As easy to setup as Yahoo! Media Player…
… but doesn’t readily display as expected. Also, hitting play bumps the corresponding text to the right for no apparent reason.
Positive: Easy implementation.
Negative: Button doesn’t automatically align to text. Can’t change color.
Source: Play Tagger by Delicious