Powershell (self) update
It would be very helpful if we could update PowerShell to newest version through PS package manager or OS included script - with all dependencies and prerequisites checks.
This is definitely something we’re thinking about and working towards. The question becomes whether it’s “good enough” to update all the built-in modules (like MS.PS.Utility or MS.PS.Management) via PowerShellGet or if we need to actually update PowerShell itself.
As we work on PowerShell Core on GitHub (https://github.com/powershell/powershell) we’re beginning to think about how more engine work might be abstracted into individual modules (which, again, could be updated async from the Gallery).
That being said, there also is probably some value in installing PowerShell Core all up via “Install-Package” or “Update-Package”. Given that PS Core is fully side-by-side enabled, you could slap down a new version of PowerShell Core next to the one from which you’re actually running PowerShell Core.
At the same time, updating Windows PowerShell (the Windows-only edition of PowerShell that sits on top of the full, .NET Framework) from within Windows PowerShell is significantly trickier because it sits in system32. Again, I think the only path forward there is putting more of PowerShell’s functionality into modules that can be upated from the Gallery.
It would be cool to be able to do this with full powershll - even if it results in needing a reboot (just like it does now). In the currently bundling with WMF, it seems like a reboot would be necessary regardless of file locking. Currently I co-maintain the chocolatey package that does allow updating powershell from within a powershell script. http://chocolatey.org/packages/powershell/