Here's to hoping that its cloudfiles implementation no longer uses a file replicated sqlite db for indexing. (iirc it did earlier on. Scared me stupid when I found out).
Can you explain why the account and container index architecture in OpenStack Swift (which powers Cloud Files) scares you? Have you really looked into the architecture or did you just hear the information anecdotally? A link to the architecture overview: http://swift.openstack.org/overview_architecture.html