Unless Windows 10 proves to be a massive improvement in performance or usability, I suspect it's uptake will be just as anemic, free or not.
If they're a small business and use OEM installed copies of Windows and those OEM copies are Pro or lower then, yes, they get a free upgrade.
If it comes with Enterprise OEM they won't get the upgrade, and if they are on a volume licence (which most companies, even medium sized are) then they won't get a free upgrade and will instead need Software Assurance (subscription upgrades).
Many companies upgrade because of non-obvious benefits, namely how newer versions of Windows ineract with Active Directory, WDS, WUS, and similar. Every version of Windows comes with new and sometimes impressive enterprise features that consumers just rarely notice.
For example, go here[0] and look at the Enterprise column. It is these types of things that are what gets enterprise excited, not how pretty alt-tab looks or if it has Cortana.
Does it come with package management yet? Can I easily avoid DLL hell these days? Can I add my own local repository and use it to maintain a fleet of workstations, making sure they always have the same configuration no matter what?
Is it easily possible to connect to a Windows machine and administer it from a command line/scripting environment? Can I disable the GUI and use Windows without tying up resources for unneeded functionality - i.e. no graphics card required?
Is all of this onboard, or does some/most of it require the involvement of a 3rd-party add-on? If its not onboard, can I validate that 3rd-party with signed keys? Is there an onboard key agent that will make this possible?
Is there an easy way to get a compiler onboard without requiring registration and so on, or does it ship with development tools already set up and configured? Are these tools usable without requiring GUI involvement - i.e. remotely?
These are earnest questions, I honestly don't know. If the majority of the answers are in the affirmative, then I'll give Windows 10 a try - it would make a nice change from what I've gotten used to with my Linux machine.
No. There is the Windows Store (all or most Metro apps, GUI) and things like NuGet for Visual Studio, but that's not what you're looking for. There are third-party solutions.
[EDIT: See sibling comments; W10 adds one.]
> Can I easily avoid DLL hell these days?
DLL Hell is no longer a concern. It's not a matter of avoiding it, it won't happen except perhaps in very unusual edge cases I'm not familiar with.
> Can I add my own local repository and use it to maintain a fleet of workstations, making sure they always have the same configuration no matter what?
You can do this. This is one reason Windows is so big in enterprise.
> Is it easily possible to connect to a Windows machine and administer it from a command line/scripting environment?
Yes.
> Can I disable the GUI and use Windows without tying up resources for unneeded functionality - i.e. no graphics card required?
In Server 2012 onwards, the GUI is optional.
> If its not onboard, can I validate that 3rd-party with signed keys? Is there an onboard key agent that will make this possible?
I am not 100% on what you want, but yes, Windows executables are commonly signed and that is integrated with the OS.
> Is there an easy way to get a compiler onboard without requiring registration and so on, or does it ship with development tools already set up and configured?
Windows does not ship with a compiler or other developer tools installed. You can install Visual Studio 2013 Community Edition, which has all the features of Professional Edition, for free and without registration (afaik - I'm doing it right now, so if I'm wrong, I'll edit). You can of course install all the free-software development tools you want. Most tools support Windows reasonably well.
> Are these tools usable without requiring GUI involvement - i.e. remotely?
Yes, although most people don't do so. I've only fiddled around. I've heard that manually fiddling with msbuild is actually more pleasant than using the GUI.
If you prefer to use the compiler and build system at the command line and you're only interested in managed development (i.e., C#), you can download the Microsoft Build tools package[1], which contains the compilers and MSBuild for headless development.
[1] http://www.microsoft.com/en-us/download/details.aspx?id=4493...
>> Are these tools usable without requiring GUI involvement - i.e. remotely?
Yes, I do most of my building on the command line. Editing, of course, is in VS, but I've also had fine success with Vim.
Otherwise your post is great.
Package management: Yes[0]
DLLs: Do not know
Local Repository: Seems to be a part of package management based on things I've seen
Command line/scripting: Powershell has been around for a while now and is quite good, but a very different idiom than UNIX shell[1].
Disable GUI: Don't believe so, but can't say for sure
Onboard: The above is all native
Easy compiler: unsure.
[0]http://www.howtogeek.com/200334/windows-10-includes-a-linux-...
DLL hell was replaced by >20GB WinSxS directory. Every version of every single DLL, regardless if you ever used or will use one. Stored forever, with no usage stats, no mechanism of trimming, no archive option for never used ones. Introduced just in time to fill ~$40 worth of SSD with data that will NEVER EVER be read again.
Not really
> Can I easily avoid DLL hell these days?
Yes, it just stores every version on the drive, seems to work
> Can I add my own local repository and use it to maintain a fleet of workstations, making sure they always have the same configuration no matter what?
For free? not easily.
> Is it easily possible to connect to a Windows machine and administer it from a command line/scripting environment?
Powershell does a lot more on this front
> Can I disable the GUI and use Windows without tying up resources for unneeded functionality - i.e. no graphics card required?
Considering Windows Server Core still has a GUI? no.
> does it ship with development tools already set up and configured?
No
Microsoft's biggest enemy is the old Microsoft that took years to update Windows XP and IExplorer 6. And then Vista happened, which brought no improvements, except a flawed and annoying security model, bloat and instability. And do I even need to rant on 8.0? So it's no wonder that users lost their appetite for updates.
However, I believe there is serious room for improvement in how we use our computers, especially our PCs. However that line on a single OS for all devices doesn't sound good to me, because there are fundamental differences between the devices in question and I hope that Microsoft will do more than marketing gimmicks and interfaces meant for tablets being shown on large screens that have keyboards.