It seems popular to criticize the Alts for coming out with only minor changes from BTC proper, but I assert that this is really a good thing instead...
Thinking about LQC in particular, the low fixed difficulty means most of the coins will get mined out quickly (under two weeks at the current rate). As a result we'll get to see how miners behave as the block rewards drop. Sure there's been lots of speculation about what miners will do when the BTC reward drops, but no one can say 100% until its tested.
By holding most aspects of BTC constant and only making small changes we effectively run a new "what if" test with each coin.
If people assign a value to a new coin and use it (for trade, exchange, or anything) then the coin lives. If not, it dies off because no one uses it and no one will trade or pay for the coins that are left.
In biology they call it natural selection. In economics its the invisible hand. Why should it be any different in crypto-coin-land?
In that context Luke's attack on CLC is like the meteor (or ice age or whatever) that killed off the dinosaurs.
If some people make or lose money in the process then so be it. Please be smart and heed Gavin's advice to avoid putting more time or money into these coins than you can afford to lose.
Labeling every new coin a "scam," "pump and dump," or "ponzi scheme" is childish and counter productive trolling at this point.
Some (or all) of these coins may prove to be poor investments or flawed experiments. And a large pre-mine has the potential to be abused, but doesn't by itself doom a new coin to failure.
I don't think the community of crypto-coin users is currently large enough to support the ongoing use of many block chains, so odds are that most of the alts will eventually fail. But they need to be allowed to fail on their own.
Another natural effect of having so many coins is that pretty soon the founders of new block chains will have to make stronger cases to attract users and miners.
Hopefully all this micro-evolution will serve to enhance the long term viability of BTC itself.