The XOXO Blog Format has been updated to be compatible with hAtom. Parsers are now expected to try to parse hAtom should no XOXO Blog Format data be present. Some sections of the format can be used with hAtom in this way, even if the data does not conform to the rest of the XOXO Blog Format. In this way hAtom can be extended, without forceing people to completely rewrite their blog templates.
The basic Blogger XOXO blog template has been updated to conform to the new format. It also has some new features, such as support for backlinks.