MovableType has the distinction of being the premier weblog application, but also has the same distinction of thus being the main target of comment spammers.
I get a LOT of comment spam every day. Most of it is handled by MT-Blacklist, but I am VERY HAPPY to see SixApart working to make further changes to the application architecture. Comments are critical to weblogs, but there are many, many websites that have been destroyed by comment spam.
TypeKey is not, for me, a valid solution. Just today, I tried to log in to TypeKey and the server wasn't responding. That's not a solution that we can count on.
