Update 2: Apparently the reason for the delay was so that Brent could take part of Sunday off. Most companies announce a delay when a feature or product is delayed by days, weeks, months -- at UserLand, a delay can mean hours! That's working at Internet speed. :-)
The "Tools" plug-in architecture is apparently being delayed, while UserLand decides how it will work and which build-in Radio UserLand features will be Tools. (my interpretation of what was said, it wasn't said quite that explicitly).
A couple of days ago I pointed some friends at the Tools stuff as a sign that Radio UserLand was getting some serious focus -- something my friends felt was missing. I guess it won't matter how long it takes to get there, if it gets there.