Actually, I used to do that by default (
https://github.com/andsens/ec2debian-build-ami/commit/0119aa17b8ffaf76002426e277a7a309278ffc94) but removed that feature because you now can mount them manually in AWS when starting an instance. The problem is that you will have some invalid default mappings when starting instances. In order for this to work with all instance types, I have to map every conceivable instance store, which isn't very pretty. You can simply re-add the code in the above link to map all instance stores (keep in mind we use euca2ools instead of ec2-tools now) or possibly write a plugin for this...?