I can not say I looked very closely at the class offerings for AU 2008, but my recollection from AU 2007 and earlier was that there was a relative parity in the offerings for AutoCAD® Architecture and Revit® Architecture (even if Revit had a "Power Track" and ACA did not).
For AU 2009, if you use the search feature on the class catalog and specify AutoCAD Architecture as the "software", there are all of thirteen AutoCAD Architecture classes (one lab) and one unconference session listed, if you count Matt Dillon's "two-part" class on scheduling as one class and eliminate the "Digital Tools" unconference and Revit Visualization class that are clearly mis-associated with AutoCAD Architecture. There are no AU Virtual classes on AutoCAD Architecture. Thanks to double-booking in some time slots, you could not schedule an entire slate of ACA classes this year, as there are time slots that do not have an ACA class offered.
Searching on Revit Architecture, on the other hand, yields a bumper crop of seventy-six classes (including four labs) and eight unconference sessions. I did not check through all of those classes to see if any were miscategorized or to check for repeat offerings. There was at least one class in each time slot and many slots with multiple choices. There are also nine AU Virtual sessions covering one or more versions of Revit, including one specifically covering Revit architecture. So if you were wondering which program Autodesk wants you to learn, wonder no more.
Make of the above observations what you will. I did not have the pleasure of attending AU in 2008 or 2009. Perhaps the ACA classes offered in 2008 were sparsely attended, and the drop in the number of classes offered simply reflects market demand. Or perhaps it is simply an extension of the marketing push to Revit. Given how much I still have to learn about Revit, I suppose I should be glad there will be a lot of learning opportunities once the recorded sessions are posted to AU Online.