D3 is potentially damaging

[ixid]

The idea of D3 is a worrying one- it suggests a number of things 
that would not be good for the success and adoption of the 
language. That the language is experimental and more of a pet 
project, that D2 has a shelf-life and will be abandoned. I can 
see D going in two directions: it can gradually grow and 
progressively gain areas where it's the standard choice or it 
will be a fairly small community of fans of an eternal language 
project. Python 2 and 3 has been a very messy split, while 
languages with a greater sense of continuity do better for it in 
my view, having one standard version of that language. Breaking 
changes may be desirable but I don't think labelling that as 
v2/v3 is a good idea, make it one thing with one suggested 
version.

What are the aims of D3 that aren't aims of D2? What could be 
done then that can't be done now? Wouldn't it be better to make 
breaking changes sooner rather than later?