Prior to SQL 2008, how would you go about declaring and setting a variable? You would do something like this:
declare @cmd varchar(100)
set @cmd = 'move /Y path/of/source path/of/target'
It takes two lines: one to declare the variable and then one more to set it to whatever you want. In SQL 2008, you can now declare and set the variable in one line:
declare @cmd varchar(100) = 'move /Y path/of/source path/of/target'
Pretty sweet huh?