A colleague of mine is copying data from SQL Server 2005 to SQL Server 2008.
The destination database lives on a SQL Server 2008 instance but is set to Compatibility Level 90. The source database lives on a SQL Server 2005 instance and is set to Compatility Level 90. He is using SQL Server Integration Services 2008 to perform the copy.
The source table, data space used (MB) is 127,072. However, after the copy is performed the destination table, data space used (MB) is 252,942. Only data, i'm not including index data space.