I am playing with your great plugin in wordpress and it's working just fine.
One thingh tough, which I think is a serious issue, is that translated pages in my wordpress install keep the original language definition.
On the website I am working on http://www.giochi01.com/, the default language is italian and the wordpress tag that print the language in the header.php are the following:
<html xmlns="http://www.w3.org/1999/xhtml" dir="<?php bloginfo('text_direction'); ?>" xml:lang="<?php bloginfo('language'); ?>">
<meta http-equiv="Content-language" content="<?php bloginfo('language'); ?>" />
Now, when I move into a translated page, let's say http://www.giochi01.com/ca/ or http://www.giochi01.com/el/, the above wordpress functions are still printing italian as the default language page.
Do you know how it would be possible to print the correct language attribute in the translated pages?!?
I couldn't sort it out by myself but I think it's an important point from SEO perspective.