Will Islam become more moderns? Maybe a strong reformist movement will come? Will Christianity regress into a stricter and less flexible form? Or are we going to have a female openly gay Pope in a couple of decades? Will Buddhism become more popular and powerful? Will there be new faiths? The return of paganism, for example, or something completely new?
Obviously, they should have died out as science replaced superstition, yet we see a resurgence of the strongly conservative ones such as Islam and parts of fundamentalist sections of Christianity that haven't waned with the more progressive parts of their churches. I think they will become marginalised in the mainstream so will try to link themselves ever more to political parties to guarantee their existence. You can clearly see the waning in countries where religion is kept out of politics and the stability and growth where they are connected. However, that is talking about "organised religion", humans are a questing people and in a world that gets more confusing everyday a search for meaning is critical to some, this is why we have seen a move towards more spiritual beliefs, especially among the young, there is quite a strong resurgence of pagan (a derogatory term coined by the new religions, although it's been taken back) beliefs which is far preferable to any mainstream church and is very nature friendly.