I was just thinking about a similar concept for language, how language evolves and what we can expect in the future. I think religion has some parallels, so please bear with me for the first bit.
I think that the modern age, with convenient transport, communication, and unprecedented levels of literacy will serve to stop the evolution of language cold. This isn't to say that there will not be variations in delivery between generations as culture changes, but I think that the presence of easily-accessed records of previous language will prevent extensive language mutation. For instance, around the time of the USA's founding the spelling of words was essentially left to the whim of the writer. Print and increased literacy has served to nail them down quite nicely, despite what the l33t-speek crowd would lead you to believe.
Cross-language sharing will not increase enough to merge languages any time soon, but the modern world serves to reduce mutation in existent language "species".
Now for how this relates to religion: The same technological advances that increase knowledge of language also increase knowledge of religion, and this is extremely damaging to their development. It is no longer possible to simply lie about the origin of a religion and get away with it, and claims of miraculous happenings are subject to a much higher level of scrutiny. For instance, with a web camera in every home it can be wondered why Joseph Smith Jr. did not Twitter the joyful news "with sauce" as they say.
In my view religions are universally based on ignorance and deception, things which become harder the more information is available. Existing religions will continue to be altered according to the whims of their practitioners however, as those from different views intermarry and the religions conform to the changing expectations of society (while stridently denying it). Still, I expect that the rate of mutation within religions will decrease with the increases in communication, but that the sharing of concepts between religions will increase dramatically.