Currently attempting to create/modify/amend a protected registry key requires convoluted workarounds or long winded scripts just to take ownership if a key that the current security principal in the runspace already has sufficient access to take ownership.
See for example the following script via Technet : http://social.technet.microsoft.com/Forums/windowsserver/en-US/e718a560-2908-4b91-ad42-d392e7f8f1ad/take-ownership-of-a-registry-key-and-change-permissions
Should really be possible either as an extension to existing cmdlets (-TakeOwnership switch anyone?) or maybe a new cmdlet, say Set-ItemOwner or such?
If there was an option to take only temporary ownership to make the change and then restore the acl as was, so much the better.