Amazon S3's new Multi-Object Delete gives you the ability to delete up to 1000 objects from an S3 bucket with a single request. If you are planning to delete large numbers of objects from S3 then you can quickly do so by using Multi-Object Delete. You can also delete object versions (in buckets where S3 object versioning has been enabled) by including Version Ids in the request.
Net-Net: Your application will make fewer calls to S3, each call will do more work, and the application will probably run faster as a result. Overall performance gains will vary depending on network latency between your client application and Amazon S3 and the number of objects in the request.
Multi-Object Delete provides you two response modes – verbose and quiet. The default XML response to a Multi-Object Delete request will include a status element (<Deleted> or <Error>) for every object. You can enable Quiet mode in the request if all you need are the <Error> elements.
You can read more about this new function in the S3 documentation.