Zerocoin was really the first of it's kind, that's where all of the hype comes from. The promise that Zerocoin offered initially was a lot stronger than anything around, and many people heard about Zerocoin long before they heard about CoinSwap or CoinJoin (and subsequently Bytecoin).

>I'm really skeptical about the wisdom of splitting up the crypto-currency adoption network effect just to introduce some new transaction features.

As someone who's been working on cryptocurrencies, I think that most of the Internet of Tomorrow is going to be driven by a set of cryptocurrencies that all do different things, following some of the primary principals of Unix. Storage and computation, for example, are services that I think will eventually find homes in cryptocurrency. Already you see things like MaidSAFE and Ethereum attacking these problems. But you also have problems that need to be solved like DNS routing, public random numbers, time synchronization where the modern solution involves centralized services.

Right now, there's not much that allows cryptocurrencies to communicate, but that's quickly changing and should move forward much more in the next 5 years. Merge mining, colored coins, and decentralized inter-currency exchanges are just the beginning.

There are a lot of problems that cryptocurrency has the potential to solve, and I think it's foolish to hope that a single cryptocurrency that will effectively solve all of them. But I also don't think that having 12 or 200 different cryptocurrencies means that any individual currency needs to be made weaker. Merge-mining is a good start, but I think that inter-currency cooperation and protection will continue to get better.