While it would be interesting to see, the actual safety aspect of this is more of an illusion than you might originally think. Changing your password just because you received a message about a failed attempt won't really make your account more secure at that time. If you have complex passwords in the first place that only you know and you don't use third party programs, then you have nothing to worry about.
In addition to this, there is a potential minor downside to this suggestion. A false sense of security like this could lead to people using easy and memorable passwords - since they are relying on the that failed attempt notification. Thus, with this viewpoint, a tool that was intended to make your account safer actually ended up doing the opposite for some people.
So other than the point that it would be interesting to see how many failed attempts there are, it's a no from me.
This post was edited by Fault on Jul 13 2012 05:58am