It's easy to say how fast Litecoin is when nobody uses it. All those altcoins acting as if they can do better than Bitcoin when they have no use at all and dont have to deal with the problems of having big volume.
Bitcoin is gold and Bitcoin is king, no coin is going to replace it.
i totally agree with @oblivi.
the problems in bitcoin will be solved by
bitcoin. there will always be market to altcoins but none of them will surpass bitcoin usage, at least not in my opinion.