I can verify; it looks like libmysqlclient15 may have been removed from the Squeeze repository very recently. I will recompile Amarok, at which point the newer libmysqlclient16 should be used instead.
Tim
I was unable to install 'amarok', after installing 'libmysqlclient15off' from 'Lenny/stable' amarok installed OK.
Wrong version 'libmysqlclient15off' in Squeeze to install 'amarok-trinity'.
-- Jimmy Johnson
Debian Squeeze Trinity 3.5.11 at sda12 Registered Linux User #380263