Demaestro - 2:19 pm on Sep 3, 2010 (gmt 0)
What you want to do is in the select portion of the statement you want to add is return the date twice once as it's true self then once as an aliased field.
Then you can add a statement that checks if it has a value, if no then make it a date way in the future.
WHEN '' THEN '3010-12-19'
END as sort_date
ORDER BY sort_date
Of course you will have to make a note to update this code in a 1000 years. By then that date will no longer be a future date ;)