There have been a number of blogs around the database unit testing space that are worth looking at.
Mladen Prajdic has written 3 blogs around unit testing/refactoring databases.
Alexander Kuznetsov – how do you unit test your T-SQL? – has had a number of comments and links to testing tools.
Piotr Rodak has written a blog around unit testing stored procedures.
It is good to see this database unit testing getting some traction out there.