From TV by the Numbers:
The premiere of Dancing with the Stars scored a 5.1 adults 18-49 ratings and 22.3 million viewers, leading ABC to a nightly win, but that was down 20% from last year’s spring premiere. Last year’s spring premiere averaged a 6.4 adults 18-49 rating and 24.2 million viewers on Monday, March 22, 2010.
The episode did feature the debut of Chris Jericho, who scored a 19 out of a possible 30 points.