Many questions here. Let me see if I can address some of them...

First, on opensourcing the OS, it is something we have considered. In all honesty, though, we simply have not yet had the time to do a proper analysis of what impact that would have, but we hope to do so. Our business model is such that this could actually be possible. Even opensourcing the hardware might be possible. Obviously changes we have made to the Linux kernel, and other opensource components, will be pushed out. Right now it's crucial to keep the whole team focused on building, but we're certainly not against doing that.

Solu is run as a service, yes, but as much as possible is cached onto the local device. You could even connect large drives to it to get even more data cached (even everything from the Solu cloud). We're very aware that people need to know they can 'export' their data, if needed, and we are providing for that need. We hope, though, that the business model sends a signal that we want to support our users, and our developers, month after month.

On the question about having phone functionality, there is definitely an argument to be made for that. Again, we needed to keep ourselves focused on delivering the best possible product with rapid execution and a relatively small, dedicated team. If we had taken the temptation (which was real) to add phone functionality, we feel we would have taken even more of a bite than what we are already doing (which is huge as it is!). Certifications, more complex antenna and electronics design, more space limitations, phone software... Besides, most people don't use their phones by their ears for most of the time. What is the device that represents true mobile computing? How do we use that?

The question about the tablet form factor is interesting. The OS and UI has very intentionally been designed to scale to many different sizes and forms. If you pop by our office you might have a chance to see it running on a tablet :-). We chose this form because of its mobility and the ability to use it neatly as a trackpad. Plus we wanted to avoid the 'yet another tablet' syndrome but bring out something really iconic and different.

On a related theme, I don't actually see desktop computing disappearing anywhere. Sure, people use tablets on the sofa, but for work, a keyboard, and an 'indirect manipulation device' (=a mouse or trackpad) is highly desirable for purely ergonomic reasons. I was once at a presentation by a 'visionary' talking about how pure mobile was the future and computers were going to die. Every single person in that room was sitting behind a laptop. There's a reason for that.

Finally, on the 'server stack' —*I love that idea! In fact, in the very earliest days of Solu, before we even had a team, I drew a 3D sketch of exactly that: several Solus stacked together to form a 'cluster machine'. One of the most fascinating ideas in the history of computing was that of the transputer. I'd still like to go that way.