Are altcoins a safe haven? No, but if you're bothered by short-term price movements you don't need a safe haven, you need to reduce the size of your investment. Only invest a significant amount when you've learned enough about Bitcoin and about investing to sit tight through minor fluctuations (and major ones as well - this week is
nothing).
For completeness, as far as investing some left over coinage into altcoins, I'd go only with alts that take advantage of King Bitcoin's network effect by either (a) operating as a layer on top of Bitcoin or (b)
sharing Bitcoin's ledger. So far no coins share Bitcoin's ledger, and Mastercoin and Counterparty are the only platforms I know of that operate on top of Bitcoin. And of those two, only Counterparty is already working and seems to show substantial promise. But again, it's not a safe haven. Your safe haven is education and contemplation on the nature of Bitcoin and investment: have some
hodling fuel.
Also, there's the indispensable
"Savings Plan" by Risto Pietila and the ensuing educational discussion in that thread: