The Inactive Google Account Policy is pretty concise; here are the key points:
At the bottom of the page, this item caught my eye:
If you want to put a hold on your account
You can temporarily suspend your Google Account. You might want to suspend your account during military tours of duty, prison sentences, religious pilgrimage, and so on.
The “Learn more” link takes you to an “Inactive Account Manager” page which doesn’t really match this text. It allows you to tell Google what to do if your Google Account is inactive for a fixed period of time – say, email a trusted friend if you don’t log in for three months. I didn’t explore that page more because I don’t actually want to set that up for my account.
I don’t have a strong or well-developed opinion on this, I just thought it was interesting.
What to do with unused or dormant online accounts is only going to become a bigger question; what should we do when our users die? I’ve only thought about this a little for work, and I’m just writing it down here so I can remember it the next time I consider this question.