Actually the OS X functionalities are moving toward those in iOS not the other way around. In other words, I think what we will see in Maverick (later this month?) will be even more like what we are seeing in iOS 7.
Well, that's a drag. It means a four step process to delete "instantly" (select Trash, select the Mailbox, select the trashed email, select Trash again)...not quite instant.
As an alternative it'd be good if they allowed a Select All in the Trash folder with the ability to deselect the mail you're not yet sure about trashing.
