I honestly believe Samsung know more than they are saying.
As for reports, we only know about those which garnered media attention. I'm sure there are incidents that were never reported to the media, just folks returned devices to the carrier or Samsung directly.
Given it seems they tried to cover up one incident, is it hard to imagine there were others that were successfully covered up.
It also seems if Samsung's own claims that the Chinese model was safe, yet we heard rumblings of reported incidents, why have they pulled all devices in China and issued a massive public apology to the Chinese people. Does the fact that they claimed incidents in China were fake and there were no problems with Chinese handset, and yet the withdrawal and apology seem like two completely polar opposites. The apology sounds more of an admittance that there was indeed something wrong.
I suspect Samsung have worked out the issue, but unless someone leaks information about it from the inside, we will never know.
There has been a post on XDA from someone who claimed to work for Samsung in Seoul saying there has already been some high powered resignations inside the mobile division because of this.
If the report of its engineers unable to replicate the issue is true, it answers the question as to whether they actually did anything after first recall ... it looks likely they did indeed simply stick a black sticker on the box and flash a firmware to make the battery green, thus never resolving the issue but at same time blaggarding and assuring their customers, the carriers and the CSPC they had.