The new feature is: human-testing anonymous comments
This is for anti-blogspam stuff. Anonymous comments will only be allowed unchecked for a given IP address for a brief period. Once thresholds are crossed, you'll have to prove you're a human to leave an anonymous comment.
The human test is just like the create account page... a distorted image or garbled audio that humans can comprehend, but not porn bots or Mel Gibson robots.
We'll be watching this closely, tweaking the rates as necessary. AOL people will be more affected by this than anybody else, since they all appear to come through a small number of proxies (and thus IP addresses). But if you don't do anon comments, shouldn't really affect you. (there's also a human test for authenticated comments, but it's much higher....)
We're also working on a way to mark a comment in your journal as spam when you delete it, and we'll take stats on reported spam (both by IP and by user) and kill accounts which were made just for spamming, or investigate IPs which are spamming a lot, if they're able to defeat our human tests. (in which case we'll mix it up and change the type of human tests randomly.....)