If by first generation you mean trusted and more or less accepted in the community, then your classification makes sense. You probably want to add Namecoin to that group, and possibly also Feathercoin.
I think the generation gap is mainly separated by technology, features and purposes. First generation coins do more and less the same thing. A coin can be considered "second generation" should be able to do more and and differentiated enough from the first generation coin. I would say all first generation coins such as litecoin, peercoin, feather coins etc., are more and less bitcoin clones. They all function and serve similar purpose and I don't think they would succeed in the long-term.
But I don't think bitcoin is the end of the internet "commodity-currency" concepts. You should be able to send messages, vote and program your coin. Second generation coins should be able to do some of these. The future belongs to "smart" money.