The holders of the coin with the least value with receive an equivalent of the coin of the higher value at the time of the merger.
how would you achieve that in a "trusted", fair way ?
Make a system which burns ANY alt-coin, and gives an appropriate amount of X coin to the user, according to burned coins current market value.
That's how you dominate markets and unite all currencies into one currency.
This idea is free to use, just let me know if you do it so i can watch the progress ^^