Hey Marc, 
[Disclaimer I'm from Scality] 
 
nice little post, but It'd be interested for me to know how you define an Enteprise Class Storage provider. 
 
AWS for example is not really catering for Enterprise customers. Well, let's say that they are trying, but their cloud storage service (S3) is mostly geared at consumer directly (developers mostly) and indirectly through Dropbox, OxygenCloud etc). 
 
I'd agree with HP and Nirvanix going after enterprises for sure. But rackspace is in between i'd say. And again, how do you define enterprise class storage. 
 
Another note, why would you list EMC ATMOS in there? They're not a service provider, only a vendor for service providers willing to offer their own flavor of Cloud Storage. Which is actually the case of AT&T Synaptic. AFAIK, they use Atmos for the backend of their service. If you start listing them, there are a few others you should be listing too :-D 
 
I guess to me Enterprise Class Cloud Storage is probably defined a bit more at the application level rather than at the infrastructure level, so any Cloud Storage provider could be listed, but the true Enterprise part of the service comes with the application that sits on top of it. 
 
OxygenCloud is a great sync-n-share application sitting on top of cloud storage (private and public). Box.net is a good collaboration tool, Storsimple is a great cloud gateway. And they're all enterprise class i believe. And there are many others of course. 
 
Anyway, this is my two cents. What do you think? 
 
Marc - @mastachand 
Scality

Hi Marc, thanks for your comment. 
 
As far as defining Enterprise Cloud Storage, I wrote that it is what "IT organizations would use for storing corporate data." In other words, infrastructure storage applications, and not including end user sync and share applications.  
 
There are differences between what a business is known for and what it is capable of. AWS caters to anybody who wants cloud computing and may be best known for supporting sync and share storage applications, but they are definitely capable of supporting enterprise storage customers with S3 too. Enterprise is an important market to Amazon.  
 
Rackspace has an OpenStack implementation which supports the same APIs as HP. It would be wrong to leave them out. Maybe I should have also listed Openstack, but that struck me as a too broad.  
 
EMC Atmos is mentioned because they are used as the backend for both public (AT&T Synaptic) and private cloud storage. You mentioned others that are using Atmos - please feel free to comment again with their names and I'll add them to the list.  
 
There are many web pages people can go to to find out about syncing and sharing services. This isn't one of them. 
 
I want to correct you on StorSimple's business too. We don't make cloud gateways, we make cloud-integrated storage that is SAN-connected on-premises and stores enterprise data locally, selecting data for storing in the cloud as snapshots, backups, archives and for DR purposes.  
 
I hope this helps you understand what this list was intended for. 
Marc Farley

Hi, Marc! I know you left off consumer clouds on purpose, but I just wanted to send you a note because CX recently launched our enterprise solution: http://bizcloud.cx.com. Besides taking stringent security precautions and offering 1TB of storage for free for the first 30 days, our collaborative features really make us stand out, including groups, chat and social network sharing. Marc, we'd absolutely love to hear your feedback, and keep spreading the good word about cloud storage! Thanks!

If an enterprise storage cloud were a box (ATMOS), everyone would own one. The reality is, that ATMOS is just one of the many object stores used to build storage implementations by cloud companies. It by itself is not a cloud.  
 
I think you should start by defining an enterprise cloud. I will throw out some attributes which *I* believe are mandatory for an enterprise cloud.  
 
Usage based pricing - How is it a cloud if you buy the box, scale the box, replace the box, and manage the box? Pay for what you use, and scale as applications and business demands.  
 
 
Engineering & field support - It is essential to have engineers and architects to assist customers in designing enterprise grade solutions using cloud storage.  
 
 
Guaranteed SLA's - Nuff said 
 
 
Data Durability - Protection from silent data corruption and bitrot 
 
 
Integration with enterprise vendors in backup, archive, collaboration...etc - A cloud isn't any good if you can't use it. Integrating with enterprise vendors to offer complete solutions to problems in the enterprise is key.  
 
 
Industry compliance (HIPPA, SOX, PCI, ETC) - Security is of most importance for enterprise customers. Clouds unable to achieve compliance, need not apply.  
 
Data locality - Enterprise security and audit teams need to understand where data lives, and control the areas which data can and cannot live. This is even more important for international enterprises dealing with data ownership laws which vary by country. 
 
Enterprise grade support - If your service only offers email support, stay out of the pool. Enterprises require 24X7X4 support. Could you imagine HDS offering email only support for a VSP? 
 
 
* Disclosure - I work for Nirvanix...You will be hard pressed to find a cloud company more aligned with enterprise requirements than us.

Thanks for sharing this list of Enterprise Cloud Storage service providers and its sound very informative I've just got here. Thanks mate