I expect that in the long run you will see dozens of moderately to highly successful cryptocurrencies. It is a fallacy to think just one will be needed. That's like expecting everyone to be happy with just one model of vehicle, or one type of fiat (imagine if fiat only existed in the form of checks, or physical coins - no paper bills, online accounts, debit cards, credit cards, etc.).

There are many financial niches out there, each requiring a crypto that is optimized with unique characteristics to best fill it. The crypto that serves as a highly secure store of wealth will not be the same as the one that best handles convenient micropayments between the Internet of Things, which will differ from the crypto best suited for paying taxes, or daily purchases at Walmart, which in turn will differ from the most convenient crypto for human payments online. Business-to-business payments will use yet another crypto. And all will co-exist with highly fluid markets between them. And that's not even getting into subjects like smart contracts and other uses of blockchain tokens. Or the potential for cryptos affiliated with a region (Auroracoin) or interest group (Dogecoin) to persist indefinitely and enjoy modest success.

Maybe I'm wrong and something will prove a jack-of-all-trades. Perhaps eventually a main blockchain will harbor a single dominant currency, and sidechains optimized for each use will function in a way that basically ties us all into a single cryptocurrency with a multitude of facets. But personally I'd feel safer with multiple distinct cryptos. It provides an alternative if devs ever royally screw one up, and competition to optimize each crypto to its fullest potential as well.

It was not the 2nd crypto.

http://themerkle.com/5-oldest-crypto-coins-spiritual-successors-bitcoin/

EDIT: Here's a better list: https://litecoin.info/History_of_cryptocurrency