Get Out Your Crayons. We Need to Color Us Some Bits

Any cloud solution would have to have inter-company SLA agreements to make this work. Even if you're going with a single vendor solution for access, it's doubtful that they control end-to-end from your datacenter to your cloud resources, and as you say, without clear mappings from vendor A queue to vendor B queue, all the packets either get re-colored inappropriately or get discolored altogether. Add in multi-vendor access and it just multiplies the mismanagement of your queues. Finally, the amount of queues available from commercial vendors is a concern if you want to distinguish the 15 applications riding on http. This is doable in your enterprise, this is possible over the carriers, but as of two years ago none of the major ones supported more than 4 queues.