What about it do you think is progressing? I mean, nothing much has happened with it recently, other than the fact that it entered the low-mining-reward phase at the start of the year -- and that's sort of a buzzkill regardless of whether it's healthy. Have I missed some developments?

It would definitely be Quark out of this list. Bitcoin - will gain slowly Litecoin - I really don't see much going for it at this point. Doge - There isn't much to say about this coin except meme and community. If people choose meme > real technological advance then we're all doomed. Quark - Already ASIC resistant and quick confirmation, and used a unique economical model. Community is actually active and working towards goal. Building mobile wallets, marketing, and gaining momentum. Peercoin - Pretty inactive community, but they have POS/POW hybrid. Namecoin - pretty inactive community, but seriously i don't think anyone have heard of anything about namecoin recently. It's incredible that it's still doing this well.