I works pretty well in the CL world, I think this approach (releases) will become standard for package management in Ecosystem-package-managers (as it has been in the OS world).
Hackage - live packages get uploaded and released fast
Stackage - a rolling tested release. It promises that all packages will compile together. (There are a few flavors of this).
and now LTS Haskell. A snapshot of Stackage that doesn't roll very quickly (every 3 months). It won't do upgrades to packages at all, except for bug fix & patch releases. So your own application code can pull down the LTS today, and again tomorrow, and be relatively sure that everything will work the same.