SQL Azure Friendly Database Versioning Idea

You seem to be asking how to store some some data in a stored procedure, which is odd, because SQL server is a fantastic tool for storing data, but not in stored procedures.

I'd say a much better strategy would be to create a very simple table to store the information you mentioned in your comment i.e.

CREATE TABLE dbo.DatabaseVersion
(
    Date datetime,
    VersionNumber decimal(5,2),
    Description narchar(40)
);

And simply write an additional row to that database on each DDL trigger.

I'd say the reasons you have against it are pretty slim, but perhaps you could create a database schema just for this metadata i.e.

CREATE SCHEMA Metadata;

To make the purpose of the table clear and change the "dbo." in the DDL above to "Metadata." Some permissions can prevent antics, and if you need to care for the table structure it is far better to do this as a first class data table than as some unstructured comments in a stored procedure.

This seems very similar to "Create a global static variable in SQL Server?" in a sense of storing some data in obscure way.

I think function would be shorter both in definition:

CREATE FUNCTION [dbo].[fn_GetVersion]()
RETURNS NVARCHAR(100)
BEGIN
  RETURN N'YYYYMMDD-HHMM and a version number and 40 chars of text'
END

... and in data retrieval:

Select [dbo].[fn_GetVersion]();

And it can be updated through dynamic DDL in triggers:

Exec ('ALTER FUNCTION [dbo].[fn_GetVersion]()
RETURNS NVARCHAR(100)
BEGIN
  RETURN N''YYYYMMDD-HHMM and version number and other 40 chars of text''
END')