Yes, exactly this.

A release where the versions of base, and all other baked in libraries are only minor version bumps and where breaking changes are localized to relatively experimental language features / extensions and GHC specific APIs would ideal. 

Eg: I'm OK having to patch ghc-mod so it works with a new intermediate GHC release.  (Esp since it uses GHC internal apis)

The new scheduler improvements, the recent doh work  , the great SIMD work / code generator improvments, the type level nats, ordered type families,  the overloaded list syntax,

All of these extensions and associated API augmentations should not break stable libraries, at least on minor version bumps, cause
1) maybe experimental new APIs can be included in minor releases as separate explicitly experimental modules (this gives a way of including new functionality in a minor release)
2) generally type checking / inference on stable code that doesn't enable new features stays the same.

I'm probably overlooking some pieces or. Details, and I'm largely restating what Johan and Manuel have communicated.

-Carter