Good extension. I'm using it (0.3.0 version) on my website though having couple of troubles.
1. In Russian language "Minimum Word Length" option doesn't work (can be partially bypassed by including short words in blacklist)
2. Blacklist doesn't understand words in Russian that begin from uppercase, so some words (beginning from uppercase) are included into keywords though they are in blaclist (written in lowercase). This also can be cured by extending the blacklist with words beginning from uppercase.