Ben Trott has announced that SixApart is moving quickly on adopting rel=”nofollow”.
TypePad subscribers are expected to have automatic implementation of the tag in the next 24 hours.
For Movable Type users, SixApart is offering a plugin (here) for using the attribute, and in a positive move, the plugin works on v2.661 and v3 releases of the product.
It is not clear yet whether future updates of the MT platform will include the attribute as standard.
LiveJournal sites will also have use of the attribute for comments for non-friends, but the time frame was unspecified.