I am decidedly depressed by the news that Justin Timberlake and Britney Spears are both slated to appear during tonight's Los Angeles stop on Madonna's "Sticky & Sweet" tour.

I know, I know…back in March, I blogged about how, for the first time in Madge's career, I was unexcited about one of her album releases. After all, Madonna's always been at her best when she's latched on to a slightly underground trend, co-opted it as her own, and foisted it onto an unsuspecting mainstream audience (think: vogueing, electronica, Mirwais). Madonna's sudden reliance on Timberlake, Timbaland, and Kanye West to make 2008's Hard Candy a sales success was tantamount to her nervously carrying her lunch tray into the pop-culture cafeteria and trying to score a seat with the cool kids when, really, she should've been sitting down at an empty table and confidently forming her own damn posse. And sure enough, seven months after its release, Hard Candy is barely on my radar, except for those occasions when the admittedly excellent "Beat Goes On" pops up on my cardio playlist.

Which makes tonight's recruitment of Spears even more distressing. Madonna and Britney's previous collaborations -- the faux-lesbian smooch on MTV, the abhorrent "Me Against the Music" -- did little to boost either singer's fortunes. And (hello!) why would you think that fans shelling out hundreds of bucks for a ticket would be excited to have a notorious lip-syncher added to the bill?

What think you, PopWatchers? Am I crazy for expecting Madge to still be setting trends at this stage of her career? And if she really has reached the "follow the leader" stage of her career, could it be time for her to (blasphemy alert) follow Celine Dion and Cher's leads, and get herself a residency in Vegas? Share your thoughts in the comments section below!