The Rolling Stones have announced that two new special guests will be joining them at their second "50 & Counting" anniversary concert at London's O2 Arena, which takes place on Thursday.  Eric Clapton and Florence Welch, frontwoman for Grammy-nominated British alt-rockers Florence and the Machine, will hit the stage with the rock legends.
 
As previously reported, two former Stones members -- bassist Bill Wyman and guitarist Mick Taylor -- also are expected to play with the band on Thursday.  Wyman and Taylor performed with the group at the O2 Arena on Sunday, when The Stones launched their 50 & Counting Tour.  In addition, that concert featured guest appearances by Jeff Beck and R&B diva Mary J. Blige.
 
Following Thursday's show, The Rolling Stones will head to the U.S. for a December 8 performance in Brooklyn, New York, and a pair of concerts in Newark, New Jersey on December 13 and 15.

Photos courtesy of rollingstone.com & ultimateclassicrock.com