It's definitely an interesting idea. From the Stackage side: I'm happy to provide testing and, even better, support to get some automated Stackage testing tied into the GHC release process. (Why not be more aggressive? We could do some CI against Stackage from the 7.10 branch on a regular basis.)
I like the idea of getting bug fixes out to users more frequently, so I'm definitely +1 on the discussion. Let me play devil's advocate though: having a large number of versions of GHC out there can make it difficult for library authors, package curators, and large open source projects, due to variety of what people are using. If we end up in a world where virtually everyone ends up on the latest point release in a short timeframe, the problem is reduced, but most of our current installation methods are not amenable to that. We need to have a serious discussion about how Linux distros, Haskell Platform, minimal installers, and so on would address this shift. (stack would be able to adapt to this easily since it can download new GHCs as needed, but users may not like having 100MB installs on a daily basis ;).)
What I would love to see is that bug fixes are regularly backported to the stable GHC release and that within a reasonable timeframe are released, where reasonable is some value we can discuss and come to consensus on. I'll say that at the extremes: I think a week is far too short, and a year is far too long.