Wow that's really cool! I wasn't sure you could register COM classes from ClickOnce.
So yes it seems like ClickOnce is great as long as you don't need per machine installs or special powers to eg upgrade the user's .NET version, etc etc.
How have you found the .application installer? (vs exe)
Edit to add: I was surprised when MS introduced .msi installers! Someone at MSFT is cranking out the installer systems.)