As the dancing queens take their last tango, has Strictly lost its sparkle?

Claudia Winkleman and Tess Daly's announcement that they are to leave Strictly Come Dancing - handing over the "sparkly baton" at the end of the current 23rd run - was a light entertainment atom bomb.

- Barbara Ellen

The pair, both reputed to be paid £150,000 for a season, present the BBC1 primetime show now slipping in ratings, down from an average of nearly 8.6 million viewers for the opening episode five years ago to just over 5 million this year.

Still, they remain the reigning queens of Saturday night TV. Which makes this not so much a departure as a showbiz abdication.

Now questions rain down like the tinsel of a Strictly final. Who will take over? Zoe Ball? Bill Bailey? Rylan Clark? And what does it mean? Not just for these presenters, but for presenting duos per se, and the crumbling concept of "Saturday night TV".