const(FAQ)

[Walter Bright]

Kevin Bealer wrote:
> Both goals are useful to some degree, but Walter is betting (as I
> read it), that in the future, guarantees about side effects and so on
> are much more useful, especially when code is scaled up and threaded.

Yes, your interpretation is correct. I think that being able to 
mathematically (and mechanically) prove things about a program will be 
increasingly valuable.