I think we already know all the uses for every metal. There are no metals yet to be discovered.

As for the value of gold, it is currently artificially held at a very low value by the world's central banks. We don't know the real current value of gold, but it is at least many times higher than the $2000 or so it's at lately.

Will it hold value as we go into the future? A very good question. It has a 5000 year track record so far, but who knows, maybe space exploration will change things.