Recently WP-Syntax had an update and the src shortcode attribute was added. It adds the reference of the source file name at the top. It is a small thing but I found it very nice.
I also find your plugin very nice especially the clean HTML styling while WP-Syntax had a problem with Twenty Eleven. It seems it was fixed in the last update though. Your plugin has nice intelligible option pages as well. So I like yours very much.
This is just a suggestion. So don't hear me if you don't feel like it.