I guess it should be easily possible to open the ssh port with a fake ssh server and collect passes (I guess they aren't plain anymore and became hashes) and corresponding logins, e.g. a honey-pot. The idea behind that is to build a database and test my accounts on those. Has anyone done that already?
If you might wonder what benefit I would expect on testing my accounts with those passwords, I would argue that passwords might change during time and I could eventually anticipate a "successful" ssh-attack.
Yes, Stephen Murdoch at the University of Cambridge has done it, earlier this year. You can read his results in the Security Research Group blog; the initial experiment is discussed in this article, and some more results appear in this article.
My personal favourite bit was
Since SSH attacks are dictionary-attacks with some flair, downloading a text file of a dictionary would provide you with a lot of potential passwords. It wouldn't hurt to set up a honeypot as that would provide you with more common passwords.
If you feel lazy however, you could download a plaintext of password dumps from major websites, as there are plenty of those around and (after filtering them for repeats) you should get a good database of commonly used passwords.
Fortunately, since human nature is a sluggish thing, you'll be good to go on that alone until people get better memory, or until someone invents a computer that doesn't need humans to input things.