With great comment spam deterrents such as this, we don’t need the rel=nofollow :)
Accessibility issues aside (for the visually impaired–which is a problem with all CAPTCHAs) — this goes beyond language and understanding barriers, i believe.
On binary bonsai, some great comments about google’s motivation beyond rel=nofollow. I personally think that if rel=nofollow is implemented on future blog versions, the motivation behind comment spam will decrease the chances that people will even care to do so. On the other hand, the whole comment spam problem was just about Google(and other major engine)’s fault to begin with.


