It is very hard to look in the future, especially when it comes to crypto currencies. But generally, I did not mention that any new altcoin has effected the prices of the old ones. Furthermore, there were no projects that truly succeeded.
The reason for being unable to predict future of coins is the volatile nature of the market but still some rough predictions could be made regarding famous coins. Altcoins such as ethereum have goof market and history as well. This altcoin alters the prices of rest of the altcoins as bitcoin does with it. But as far as new coins are concerned, they need couple of years in order to put influence on other coins.