After hearing about the "Keep on the Watch!" convention, I could have sworn they used that one before. So I searched around the internet. I guess I was wrong, it's just a common slogan that I'm sure they've used often enough, just not as a convention theme.
But, for anybody who's interested, here's the list I've compiled:
1942 - New World
1943 - Call to Action / Free Nation's
1944 - United Announcers
1946 - Glad Nations
1947 - All Nations Expansion
1950 - Theocracy's Increase
1951 - Clean Worship
1952 - Press On to Maturity
1953 - New World Society
1955 - Triumphant Kingdom
1957 - Life-Giving Wisdom
1958 - Divine Will
1959 - Awake Ministers
1960 - Peace-Pursuing
1961 - United Worshipers
1962 - Courageous Ministers
1963 - Everlasting Good News
1964 - Fruitage of the Spirit
1965 - Word of Truth
1966 - God's Sons of Liberty
1967 - Disciple-Making
1968 - Good News for All Nations
1969 - Peace on Earth
1970 - Men of Goodwill
1971 - Divine Name
1972 - Divine Rulership
1973 - Divine Victory
1974 - Divine Purpose
1975 - Divine Sovereignty
1976 - Sacred Service
1977 - Joyful Workers
1978 - Victorious Faith
1979 - Living Hope
1980 - Divine Love
1981 - Kingdom Loyalty
1982 - Kingdom Truth
1983 - Kingdom Unity
1984 - Kingdom Increase
1985 - Integrity Keepers
1986 - Divine Peace
1987 - Trust in Jehovah
1988 - Divine Justice
1989 - Godly Devotion
1990 - Pure Language
1991 - Lovers of Freedom
1992 - Light Bearers
1993 - Divine Teaching
1994 - Godly Fear
1995 - Joyful Praisers
1996 - Messengers of Godly Peace
1997 - Faith in God's Word
1998 - God's Way of Life
1999 - God's Prophetic Word
2000 - Doers of God's Word
2001 - Teachers of God's Word
2002 - Zealous Kingdom Proclaimers
2003 - Give God Glory
2004 - Walk With God
2005 - Godly Obedience
2006 - Deliverance at Hand!
2007 - Follow the Christ!
2008 - Guided by God’s Spirit
2009 - Keep on the Watch!
To me, they're like business slogans. More-or-less meaningless slogans that are supposed to pep you up and get you excited.
It's interesting to see the lack of creativity in some spots. Look at '71 - '75: Divine Name, Divine Rulership, Divine Victory, Divine Purpose, and Divine Sovereignty. And again with "Divine" in '58, '88, and '93. And the Kingdom ... in '81 - '84.
It's also interesting to see some themes like "Kingdom Loyalty" about the time Ray Franz left.
Or 71-75 was a whole "Divine" theme. Almost as if they were leading up to something in 1975...
It would almost seem that with this year's "Keep on the Watch", they may be trying to regenerate some of the urgency that's been lost by the changes in generational teachings.