Which OS license will you use?
I think it's important. You've got GPL, LGPL, BSD, Artistic, etc. My preference is GPL. A lot of people like the BSD style too.
I think you should stick to a major license if you can, GPL or BSD. Just because you OS something doesn't mean anybody's going to pay attention to your product. There are plenty of great ideas that didn't make it in OS land. I'm not sure why some things flourish and other things die while others linger.
There are plenty of examples. The Linux kernel is wildly succesful, the HURD is not moving very fast, there are all kinds of dead Windows clone OS efforts.
You'd think one of the many Windows kernel efforts would be a major success because everybody wants apps, everbody already knows it and how it should work, etc. Perhaps Wine killed those efforts, or maybe the programmers who actually do the work just aren't inspired by Windows. Who knows?
The HURD is still alive and kicking and I hope to use it someday. Considering the pedigree of the HURD I'm surprised it's not going head to head with Linux already. For the most part the OS programmers love the GPL and from a cultural perspective you'd think the HURD would bleed off talent from other OS kernels (Linux) just because of that. Perhaps it's a 'cult of personality' type thing. With all the commercial Unix vendors making significant code contributions to the Linux kernel it's going to be difficult for HURD to keep up let alone catch up.
Why did Linux succede? I'm not sure. Partly because it was GPL'd? Partly 'cool factor'? Partly because it fed on the minix kernel programming community (attracting them with the GPL and a much more open development process?)? Right place, right people, right time?
Maybe you should define what advantages your software provides its users. Why would those advantages be increased by OSing. Why would a programmer work on this code for free. What license would attract/repel intrested programmers? Who will these programmers be? System administractors, hackers looking for a 'cool' outlet for their programming creativity, technical types within a specific industry (former customers), or something else?
I'm intrested in your answers to the above questions.