I would like to point out that the failing of wave was primarily that nobody found it to be useful, not that it was over-hyped. I can't imagine NaCl having that problem.
I don't want to go off on a tangent but I think it's a relevant point that the overall usefulness of both technologies is strongly related to having diverse implementations. I'm not saying hype is the issue but rather the trying to get cooperation from the industry and competitors when the feasibility of the project isn't entirely proven.
Wave was definitely overhyped. That's why so many sought beta invites and why so many were confused and disappointed when they finally got in.