This page is our road-map for what will be in 8.0.
We hope to incorporate all the "Landed" and "In-flight" stuff under "Release highlights" below.
We'll include (or at least review) all patches in tickets in "Status: patch" below.
We will address all the tickets under "Status: new" below with "highest" or "high" priority. We love help to do more, but there are far too many "normal" tickets to make any promises.
If you believe your favourite thing belongs in this list, but isn't there, please yell. If it's not in the road map, it probably won't get done. Without a lot of support, many things in the road map won't get done either, so we need your help!
Release candidate by mid-January 2016. Release in mid-February 2016.
Use Cxt in Template Haskell's representation of deriving clauses ( Phab:D1202)
Fix #10845 with Phab:1422 (Rework the Implicit CallStack solver to handle local lets)
Support for reasoning about kind equalities, which gives promotion of GADTs to kinds, kind families, heterogeneous equality (kind-indexed GADTs), and * :: *. There is some discussion in DependentHaskell/Phase1, but that's very low-level. I (Richard) have no good user-oriented write-up yet, but there shouldn't be much in the way of new syntax -- just fewer type errors. ( Phab:D808)
Simon PJ's wip/spj-wildcard-refactor branch, which refactors the handling of implicit binders and wildcards
A huge improvement to pattern matching (including much better coverage of GADTs), based on the work of Simon PJ and Georgios Karachalias. For more details, see their paper. ( Phab:D1535)
Backpack is chugging along; we have a new user-facing syntax which allows multiple modules to be defined a single file, and are hoping to release at least the ability to publish multiple "units" in a single Cabal file.