I have another linux server running here could I copy the mysql /debian.cnf file from there into the malfunctioning server's debina.cnf file?
Probably... it will end up with the same configuration as that system <fingers crossed> ... but dont forget the my.cnf files too.
Or you could edit the debian-sys-maint password in you existing conf... then add the root user, then add you.
If all else fails:
# apt-get remove --purge mysql-server
# apt-get install mysql-server
In the course of mulling this over, I found the following wee gem: