(IT, Business and Social Strategist/Commentator, SummaLogic LLC)
Inside the enterprise Nebula will face the 'box of a different color' problem. I've always counseled appliance makers to offer their products with interchangeable bezels which can be painted the same color as the predominant technology in the customers data center. That way the operations team doesn't notice them in the rack. Obviously this is tongue-in-cheek... But, the point is valid. Penetrating an IBM, HP, Dell, Cisco or Oracle dominated data center is really, really hard. Just ask Cobalt Systems - their success was mostly in web hosting providers, not in the enterprise. Nebula will find a niche in the enterprise. If it is going to be really successful in this space it will need to clearly differentiate itself. Are Open Stack and the Open Compute Project enough to do that? I'm not sure. I may change my thoughts on this as more on the specs emerges. That niche could get quite big if they do this right.
So that leaves the big area between the really small (Mom and Pop) companies and the really big players (big enterprises, Amazon, Microsoft, Teremark, et al). And it could be a 'target rich environment' for Nebula. Many medium-sized companies (let's say greater than 1,000 employees) may have an interest in building a private/hybrid cloud infrastructure and an easy-to-use appliance such as Nebula fits the bill when it comes to reducing the variability and complexity of building and managing a cloud infrastructure. And OpenStack gives them the interoperabililty and portability they desire - especially as OpenStack gains more traction (which it will).
I like the Nebula model and I hope it is successful. Especially from the OpenStack perspective. We need openness, interoperability and portability. I'm not quite as excited about the Open Compute Project / appliance side of the equation. But, they are one of the early entrants into providing an OCP platform, and if the management platform that supports it is simple, elegant and easily integrates with existing management tools, then it could be a winner. It will be interesting to see how they approach things like technology refresh, patch management, etc. If they do this right then they score big points in my book.