Here are some great Etsy plugins for WordPress. I included the Plugins home page's Page Rake (PR) so that you can better judge it's stability.

1. Custom Etsy Widget - http://wordpress.org/extend/plugins/etsy-widget/ pr3 This plugin adds a sidebar widget that is similar to Etsy Mini but allows control of styling and other parameters.
2. Etsy Treasury Posting Tool - http://2slick.com/web/wp-admin/plugin-install.php?tab=plugin-information&plugin=etsy-treasury-posting-tool&TB_iframe=true&width=600&height=550 pr0
   
3. Customizable Etsy Widget - http://wordpress.org/extend/plugins/customizable-etsy-widget/ pr3
   This widget displays Etsy items (from favourites or store) in a widget, without using flash or an iframe, which allows greater theme integration.
4. Etsy Shop - http://wordpress.org/extend/plugins/etsy-shop/ pr3
   This plugin allows users to insert Etsy Shop in posts or pages using the bracket/shortcode method.

Make sure to check if these plugins are compatible with your version of WordPress. To check your version of WordPress pelase read this: check wordpress version