TransactionManagementConfigurer with 2 platform transaction manager

I am still confusing the use of using the new Spring 3.1 TransactionManagementConfigurer to configure multiple transaction manager.

It seems to me that when the application try to autowired @Transactional, behind the scene, it will invoke annotationDrivenTransactionManager() and determine which Transaction Manager class will be used.

However, for @Transactional, I could provide optional bean value name for the desired transaction manager to be used. e.g. @Transactional(value=txManager1). The annotationDrivenTransactionManager() didn't accept the value parameter for me to choose the desired transaction manager be returned.

Am I miss something for TransactionManagementConfigurer?