You're right -- this isn't, and won't ever be (as long as it stays with this technology) up to Bret's standards.

However, Bret's stuff doesn't exist, and there's a reason for that: it's really hard. What these guys are doing is trying to make something that actually works, and it looks like they're doing a pretty decent job of it. The fact that it integrates with all the normal tools (in particular, LaTeX) makes me inclined to overlook it's imperfections.