It replaces export data in SSMS by offering dependency aware order of table transfer.
You can chose to build dependency tree for your tables in order to transfer parent tables first and child tables after. You don't have to run data export wizard multiple times.
Wizard assumes that you already have destination tables in place. You can generate object scripts in SSMS and create destination database using that. Then use this wizard to transfer the data.
For now, wizard does not support transferring table diffs, only full table data.
Wizard is built around .NET and SQL Server SMO and uses bulk transfer for data transfers.