+1 to this. If Bitfloor comes back, I would trust it a lot more than any new exchange that might come to take its place, because I know Bitfloor has learned its lesson the hard way already, and hopefully won't have to learn it again. A new guy will probably fall into the same "oh, it won't happen to ME" trap that Roman did.
Sorry, but that's flawed reasoning. You are saying you trust people more because they have proved they are not trustworthy. By that reasoning you should trust bitcoinica with everything you have.
No, I am saying I trust people more who have "learned their lesson" already vs people who haven't. I trust someone who has been through the hell of losing $200k of customer funds more than someone who hasn't, because they're going to do everything in their power to make sure it doesn't happen again. They will have better security practices, procedures, and knowledge the second time around.
Of course, that's not a statement that stands entirely on its own. Obviously, I will do my own due diligence to make sure that they actually have implemented better security measures, and that I am satisfied with the way they have resolved the prior security breach, etc.
It's like riding a bike up a hill. Some people may try to ride straight up the hill, but it is too steep to do it - they will fail. Others will take the longer path that winds around the hill. Now, I don't know who is taking the path and who is trying to ride straight up, but I know that if someone DOES try to ride straight up, and fails, they're unlikely to try it again. Therefore, anyone who fails is more likely to take the longer path that winds around than anyone who hasn't failed yet.