I'd like to join the people saying that I find Echo uncompelling. I had a post ready but I wanted to check something first, so I sent an email to Dave Winer that is probably at least partially responsible for the could somebody else write a spec for RSS 2.0 question on Dave's FAQ. That post covered almost point for point the rest of that FAQ ;-), with a heavy emphasis on the point that Dave is demonstrably not in control of RSS, proven by the very incident that started this whole thing.
The way Dave answered it renders most everything else I wanted to say redundent, but I would like to say that I still think this is a good approach, which is why I asked about forking the spec in the first place; some of the criticisms leveled against RSS by the Echo crew are valid, but underspecification can be at least partially corrected. The only thing I'd disagree with is the words Yes, of course. in Dave's FAQ; it is not immediately obvious that that would be legal. It's easy to get copyright notices wrong when reading them.
The other comment I want to preserve is that despite our common sense, the foundations of an organization and the leaders of an organization exert a huge influence on the final outcome of any process. In my opinion, Echo is largely predicated on a lie ("Dave Winer has too much control over RSS."), and led by people who were willing to believe it, despite the evidence to the contrary sitting right in front of their face. It is exceedingly unlikely that anything great will come of this, because it makes it extremely likely that the organization will flame out.
Now, the certainty isn't 100%, and if anything does come from Echo, we must judge the final product on its own merits. But given what the Echo organization is built on, I still think it extremely likely that one of two scenarios must still occur: Either the Echo effort will fly apart at the seams as everyone insists on having their say (and that's one of the main driving forces of the project), and the end result (if any!) will be too complicated and bloaty to be useful, or somebody will have to "put their foot down" and in the process annoy people a lot, resulting in an Echo spec that will be in all probability a slightly-better specified RSS, but with worse political problems then RSS, coming from how it was "born".
This was not worth splitting a community over, and I have a hard time envisioning an honest scenario where Echo provides any real improvement. (Sure, I can imagine a happy-fun world where everybody developing Echo gets along great and things progress smoothly towards a great spec and nobody ever gets political because their feature was bent, spindled, or mutilated and the end result is so compelling everybody falls over themselves to implement it and everybody in the end is just one big happy family... but we don't live in that world, and that's not how it's going to go. Predictions based explicitly or implicitly on that premise do not impress me.)
And yes, I support Dave; his leadership is a big reason the weblog world is different from other ones. And sometimes leadership means saying things not everybody wants to hear, but that need to be said.