History of the Bible shows that it not only has been altered a lot in the past but is itself a rewrite of older scriptures. Each time someone goes back to the original texts from the original scriptures, they tend to find a slight variation.
Thing is, the bible was written to be a bit vague to begin with. This was so more people could relate to it and be more likely to join. This helped greatly increase the numbers of followers. Problem is, when a religion get large, the slight differences become dividing points. This cause a different religion to form and they tend to change the scripture to define this. We have seen many changes recently in the Christian faiths. Some have decided to accept things like homosexuality and even evolution. The irony here is it shows religion adapting to survive. Topic like homosexuality could give the religion a bad reputation so instead of loosing members they adapt to the media. Seeing that topics like evolution are being shown to be much more probable, again, religion works to include it as part of their faith. In this case, they tend to use the idea "Sure, evolution may be true, but God did it."
Just did a bit of research. One site alone lists 46 different version of the Bible in English alone.
This clearly shows that your statement "I know there is and always will be one LITERAL Bible" is wrong and there are at least 46 literal versions of bibles known.
There's always the possibility of another piece of text surfacing that is either completely different from the bible or revising the bible so it can fit with modern times, Will it happen? Chances are, it probably won't. If it does ever occur, no doubt it could cause controversy and backlash. All depends, really.
I am not certain when this would or could occur, but I am confident that a new religious text could rise to the level of the Bible and even beyond someday. It would require a religion to become more dominate than Christianity. In my mind, this is entirely possible, although it could take quite some time.
Point being that the King James version is not the original untouched Scripture. Much meaning was lost through three(!) translations, from Hebrew to Greek to Latin to Early Modern English. And the New Testament wasn't even originally in the same language. So I think the only "true" Bible would be in the language it was first written down in. But even there, even Hebrew wasn't the original perfect language from before the Tower, and for the Word of God to be "perfect," it could be argued that it would have to be in the original, perfect language.
Since the Bible we have already had the Koran, the Book of Mormon and Dianetics among others. So to see a "new bible" in the future ignores the fact that it has already happened. But I am pretty sure more will pop up, I mean some fools think the Spaghetti monster is real, so that could produce a new bible.
If Jesus was God then there is no further official revelation to be given. As such there is no ability to add to the bible as once you have the direct word of God there in no need to add further to it. That is why the canon was closed after the death of the last Apostle.
According to our current Bible the 2nd coming of Jesus is supposed to be the end of time. We could possibly have more added, but it would be a contradictory Bible. It would also take quite a long time for this new Bible to be written. Who knows, I am Catholic, but maybe I am wrong.