This is not a new discovery, it is just the first time it has been presented like this:
http://www.huffingtonpost.com/2009/07/06/historic-bible-pages-reco_n_226045.htmlLONDON — The surviving pages of the world's oldest Christian Bible have been reunited _ digitally. The early work known as the Codex Sinaiticus has been housed in four separate locations across the world for more than 150 years. But starting Monday, it became available for perusal on the Web at so scholars and other readers can get a closer look at what the British Library calls a "unique treasure."http://en.wikipedia.org/wiki/Codex_Sinaiticus
The differences have been long known. Despite what the "inerrant bible" people will tell you, some manuscripts contain different books as well as variations in biblical text.
The Christian Bible is largely pieced together and certainly they are copied from copies and other sources. As you might know, the "original" texts were not typically put together or written at the same time or in the same languages. This codex, like the bibles we have today, was pieced together from different sources and handwritten by probably 3 or 4 scribes (and then several "correctors" also had a hand in it.
This particular Codex has numerous books that are not in other Codex.
In some places you can see where the scribes revise what other scribes write.
http://en.wikipedia.org/wiki/Codex_SinaiticusAlong with Codex Vaticanus, Codex Sinaiticus is one of the most valuable manuscripts for establishing the original text — see textual criticism — of the Greek New Testament, as well as the Septuagint. It is the only uncial manuscript with the complete text of the New Testament, and the only ancient manuscript of the New Testament written in four columns per page which has survived to the present day. Only 300 years away from the original manuscripts of the New Testament, it is highly important and considered a very accurate copy as opposed to most of the later copies, "preserving obviously superior readings where the great mass of later manuscripts is in error".
In the Gospels, Sinaiticus is the second most important witness of the text (after Vaticanus); in the Acts of the Apostles, its text is equal to that of Vaticanus; in the Epistles, Sinaiticus is the most important witness of the text. In the Book of Revelation, however, its text is corrupted and not good quality; it is inferior to the texts of Codex Alexandrinus, Papyrus 47, and even some minuscule manuscripts in this place (f.e. Minuscule 2053, 2062).
The Bible people have today (especially the Christian bibles) are largely a best guess at what the "originals" were. There is no "one" accurate text.http://en.wikipedia.org/wiki/Biblical_manuscriptThe Textus Receptus for example which is used for the base of translations like the King James bible has been noted to have more than 30,000 text variations with other sources
http://en.wikipedia.org/wiki/Textus_Receptus#Textual_criticism_and_the_Textus_ReceptusJohn Mill (1645-1707), collated textual variants from 82 Greek manuscripts. In his Novum Testamentum Graecum, cum lectionibus variantibus MSS (Oxford 1707) he reprinted the unchanged text of the Editio Regia, but in the index he enumerated 30,000 textual variants.
You see it is quite impossible to say that there is such a thing as an inerrant bible because some have different text and even complete missing books or chapter segments. That means people over the past 2000 years have had to pick and choose what is and error or not for modern day readers. You cannot say that all the texts are correct and have to conclude that some of the texts are in error.