The examples from this video does not seem to work with the (October 2008 CTP) of the "Oslo" SDK  Version 1.0.0925.0 currently avaiable at

The spouses 'SpouseA' and 'SpouseB' in the 'Marriage' type does not get the correct data type which should be
the identity key 'Name' nvarchar(28) from the table 'People' .
Instead it get's a nvarchar(max) so the constraints for the 'Marriages' table does not comply.

I get the following errors when running mx.exe

Installing Image: Contacts;Version=1.0;Locale=neutral...
Column 'Contacts.People.Name' is not the same length or scale as referencing col
umn 'Marriages.SpouseA' in foreign key 'FK_Marriages_SpouseA_Contacts_People'. C
olumns participating in a foreign key relationship must be defined with the same
 length and scale.
Could not create constraint. See previous errors.