The SQL Server running in a VM is precisely the part you no longer have to worry about. Drive by contributors aren't going to do this when offering ORM patches. But if they have an easy way to test on Linux it becomes a lot more viable. Going back to Django, we provide a vagrant image with most databases preinstalled. Adding sqlserver to this setup will now make sense.
Also Microsoft are deprecating the old bindings and are creating new ones I believe will be open source. I might be off slightly.
> Adding sqlserver to this setup will now make sense
I would strongly recommend you check SqlServer license terms first; the last thing you want is to make any of your downloaders liable for license payments as soon as they start the image. I really don't think what you suggest is possible, because you would be redistributing SqlServer - maybe with the Express version, but that was pretty crippled last time I checked.
Also Microsoft are deprecating the old bindings and are creating new ones I believe will be open source. I might be off slightly.