Dates in SQL Server aren't stored in any of those formats. They're stored as a number of days since "day 0" (1/1/1900 by default). The formatting you are seeing is done by the application layer, whether that's SSMS or something else.

For example, today (6 August 2012), on my dev copy of SQL 2008 R2, is stored as 41125, since that's the number of days since 1 Jan 1900.

Try this:

SELECT CAST(GETDATE() AS INT),

DATEDIFF(DAY, 0, GETDATE());

If you want the display to be different, change the settings in your application, or use a Convert mask for it.