If you think that implementors are going to go ahead and code to anything we can come up with, you are barking up the wrong tree. However, if we define a minimal set of features as 'CLtL3', and provide a reference implementation, there is a chance that it might gain hold, and users might demand CLtL3 compliance from vendors.
Slightly off topic, but if I might enquire.. when you say provide provide a reference implementation, does that mean picking one of the open source CL implementations and developing it to include everything that CLtL3 specifies?
Malcolm