Some time ago I wrote a test post with a Google Wave embedded into the post. Only a couple days ago I discovered that to make a Wave public one needs to add firstname.lastname@example.org as a participant to the wave. I did that and the Wave became visible also to people without Wave accounts. But another fun thing happened at the same time - multiple people reported that this Wave popped up directly in their Google Wave Inbox. But in this case I suspect that when people saw the Wave (even in it's disabled form) either on my blog or on the Planet Debian, Google stored that info somewhere and when they logged in their new Google Wave accounts it added that wave to their Inbox, but the wave did not show up in their Inbox until I made it public a couple days ago. And thus there was a disconnect between action (people viewing my blog post) and reaction (Wave showing up in their Inbox) that will confuse a lot of people.
The way to fix that would be to only add waves to your Inbox if you've commented on them (or added to them) which would not be possible for private waves.