It has been suggested that the current RESTful API specification doesn't cover every use case, and is probably not specific enough for implementers and consumers of the RESTful service to have a clear picture on how to use it and/or what to expect.
Some of the threads on this topic:
Louis Ryan also added (on a different topic thread):
"I think the issue here is that if the RESTful API implicitly defines CRUD operations on all these types then the semantics of each of those operations needs to be documented or at least stated that they are not defined.... containers are likely to diverge without guidance."
The consensus seems to be that we would like to see the RESTful API specification to be more detailed and, well, specify what exactly to expect from it and go into more detail on the pieces that it inherits from the http / atom / atompub specifications and how their applied here.
However we don't have anyone yet to champion this, so i'm hoping to see someone volunteer :)