goodroi - 12:06 pm on Oct 12, 2012 (gmt 0)
In June of this year, Matt Cutts announced that 99% of people being impacted by a manual penalty imposed by a human Google reviewer were being notified. In the past Google did not do this and there is no guarantee how long they will do this.
To further confuse things there is a chance that a website can be impacted by a combination of an unannounced automated penalty & a notified manual penalty.
Since Google does not work for us and since many SEOs are seeking to exploit any weakness in Google's ranking algorithm I would not expect Google to make things easy for the SEO community.