On Wed, Nov 3, 2010 at 5:50 AM, Isaac Dupree
mtl-2.0 was just recently uploaded. If it's easy, I would cautiously wish to wait a month before committing-for-sure to mtl-2 in the platform, and see if there are unexpected transition difficulties. Any issues that users notice will surely get mentioned on the mailing-lists. Though, the proposal page (and past experience with transformers/monads-fd) does seem to have investigated the difficulties pretty well; and if the difficulties are not much more than estimated, then they seem worth the costs to me.
We have about a month and a half to figure it out. During that time we'll try to migrate all HP packages to mtl-2 (and perhaps some other important packages.) If that doesn't cause problems, we can go ahead with mtl-2 in the next. Release, if it does cause problems, well then mtl-2 will not make it. Put another way, all accepted proposals are conditionally excepted on actually being possible to implement. :)
(Is there time pressure? Given http://trac.haskell.org/haskell-platform/wiki/ReleaseTimetable I am not sure. Incidentally it suggests that we technically missed the proposal deadline by one day depending on timezones - Nov 1 vs Nov 2 - which I'm not inclined to worry about. The page history says Don Stewart wrote that timeline mid-July.)
That's my (and the rest of the steering committee's) fault for not calling for consensus sooner when the discussion died out. My apologies. Johan