After the SPS configuration wizard was done, I tried accessing the SharePoint Central Administration page… and got this:

 

 

I stopped looking at the event log at this point, what proved to be a time-costly mistake, more to that later. I started searching the Internet and found a lot of similar cases but none came close to mine. Most “answers” told you to disable IPv6. Seriously guys, this is NEVER a “solution”! It is at best a workaround… and won’t help in my case anyway. A little later I reviewed our MOSS documentation and stumbled across the solution: the application pool identity user did not have enough rights on the server. I forgot that using a “domain admin”-service account does NOT grant it the right to log on as a service! I really don’t like this behaviour as I like to start with a domain admin account and then, in case everything runs as expected, strip it to a least privileges account. So I added the service account to our server GPO and the application pool started and could reach the Central Administration site.

This is just another case of READ THE EVENTLOG CAREFULLY! There was a third entry I overlooked which even suggests the missing log on rights: