openxml vs xquery behind the scenes ?

Also, with regards the changes from Sql 2000 to Sql 2005.

When dealing with parsing/querying xml within a stored procedure, what is the difference (internally to sql server) between using OPENXML and xquery statements within a stored procedure ? With openxml, you need to call sp_xml_preparedocument, which will load a special version of the msxml parser called msxmlsql and loads the entire document into memory.

One thing that I like about XQUERY is that you can use the CROSS APPLY join to process database XML data on a row by row basis. I am new to using XML so I am also interested in hering the answer.