I had been working in SQL Server 2008 for a number of months while working on the upcoming 2008 books and never had experienced this issue until just today. In hindsight, I can't imagine how I didn't experience sooner. The behavior change is when you save a table in Management Studio that requires the table be dropped and recreated behind the scenes, the change will fail by default with the below warning. In SQL Server, tables are dropped, recreated and reloaded automatically for you without having to worry about what's going on behind the curtains but this may create issues for some users. This behavior is required upon a number of actions but most common is creating a new column in a specific location in the table.
Saving changes is not permitted. The changes you have made require the following tables to be dropped and re-created. You have either made changes to a table that can't be re-created or enabled the option Prevent saving changes that require the table to be re-created.
This is by design and can be quickly fixed in Management Studio by unchecking a property. To fix this in Management Studio, go to Tools -> Options then go to the Designer Page and uncheck "Prevent saving changes that require table re-creation".
-- Brian Knight
Huge thanks for this. I love when someone clearly answers a question I have :-).