It seems there may be one more gospel to add to the list of the non-cannonical ones. According to the finding, a series of gospels found in the 1970's has been carbon dated to be from about 300 AD. While this certainly puts it after the time it would have been written, it is believed to be a copy from an earlier document which was believed to exist due to a reference from a bishop in 180 AD.
The new gospel is written by Judas, the disciple that betrayed Jesus and apparently reports that this was done at Jesus' own request.
So where does this gospel fit in the timeline of the writings of gospels? The cannonical gospels were all written between ~65AD and ~120AD. Thus having a text that is being written about by bishops only 60 years after the Gospel of John was written makes it likely that is authentic.
But for those that don't know, there's more than just the four gospels that made it into the Bible. Others, such as the Gospel of Thomas, may very well predate even the earliest of the cannoncial gospels, while others, like the Gospel of Mary (which is the basis for the DaVinci Code), give a very different view on the events that took place during the time period.
Yet neither of these texts are accepted as "true" by any of the main branches of Christianity (at least that I'm aware of). Similarly, I expect that this newly discovered Gospel of Judas shall be quietly shuffled off to the side by priests, and only a topic of interest for religious scholars.
To me, this would be akin to trying to read a novel with only the Cliff Notes and presuming that they're adequate. In astronomy, this could be compared to studying the universe only in the optical wavelengths dispite the many more we know about today. To me, if a tool is available to gain insight, there is no reason not to use it.
Unless your goal isn't to gain insight of course. It is precisely this reason that Creationism and it's younger brother, will never pass as science. As Behe proved on stand at Dover, such people aren't truly out to use the tools they have available to them, which is why Behe was forced to admit that he has never tested a single one of his hypothesies on irreducible complexity (as if you could really test such an assumption anyway).