It remains to be seen how the excitement around Rails will affect attendance this year. Attendance rose sharply last year in October on the buzz around Ruby in general and Rails in particular. Will the conference be kept small like last year, capped at 200? Registration should open soon and we'll find out.
There have always been strong links between this event and the Agile community, including attendance and talks by Dave Thomas, Martin Fowler, Ron Jeffries, Brian Marick, and other Agile practitioners and mentors.