I just installed this plugin and I have to say that I really appreciate the simplicity. However, it's a little too simple. It would be nice to be able to:
-Disable the plugin on pages or on certain posts.
-Choose the sharing button style that you'd like to use
-Add the ability to add your own buttons (Instapaper, email, etc.)
All in all, it's a great start, though. Good work, guys!