GigaOM received confirmation late last night that seven developers are leaving OpenStack open source cloud project co-founder Rackspace Hosting to join up with Nebula, which is working to develop private cloud infrastructures using OpenStack as a core.

Most of the seven were veterans of Rackspace acquisition Anso Labs, itself the San Francisco-based consulting firm which helped NASA create Nova, the cloud computing platform that would go on to form the core of Nebula, the agency’s internal cloud – which would, in turn, eventually mature into OpenStack, with the help of Rackspace Hosting.

That’s why it’s not so shocking that these seven OpenStack developers would end up at Nebula. Nebula CEO and co-founder Chris Kemp was NASA’s first-ever CTO in his former career, and can claim to be a co-founder of the OpenStack project itself. Rackspace’s Anso alumni worked closely with Kemp at the outset of OpenStack’s rise to stardom, he tells GigaOM, and it seems that to a large extent, Kemp is merely getting the band back together.

It’s important to realize that even though Rackspace co-founded the OpenStack project, and a major contributor, the hosting provider is increasingly aggressive about shedding its financial and visionary control over the cloud platform’s development and handing the reins over to the community in the form of the OpenStack Foundation (of which Nebula joined as the first official member last week, incidentally).

What that means here is that Rackspace is gearing up to offer large-scale commercial cloud services based on OpenStack technologies for the very first time. But the hard work has already been done, and GigaOM’s anonymous source within Rackspace confirms that the departing engineers are looking for an environment (and presumably a challenge) more akin to a startup. And given that Kemp and Nebula have been huge evangelists for OpenStack as a platform and a cause, it seems to be an utterly natural landing pad for the seven as they’re likely looking to continue contributing to the project’s future.

But knowing what we know now, this news certainly doesn’t say anything to me one way or the other about OpenStack’s role at Rackspace (Rackspace still has plenty of OpenStack talent onboard, I hear), about the maturity of the platform (as HP and others join Rackspace in the ranks of service providers bringing OpenStack-powered services online), or about the OpenStack developer community at large. It’s more about a group of engineers looking for a cultural shift and new horizons, and if that’s surprising, you haven’t spent much time in Silicon Valley.