I love this plugin; thank you! It has all the essentials without a lot of bloat from unnecessary share options. I would like to see the Pinterest button updated, though, to behave as the browser's Pin It button does.
If you click on the "Pin It" button in your browser, it will auto-fill the Pin description with the text from the image'stitle field. The alt tag can then be used for its more classic purpose of providing a literal description of the image for the visually impaired. Currently, the Pinterest button in the plugin auto-fills the Pin's description with the text from the alt field. This means that bloggers can't use one or the other when optimizing images for Pinterest.
As a side note - it's far less important, but it'd also be nice to be able to add the "call to action" before the buttons at the bottom of the post but not the top. (I like having the buttons on top also, but the text gets to be a bit much.)