343 Industries has been slowly porting Halo: The Master Chief Collection over to PC for some time now, but one thing not yet mentioned would be the possibility of seeing crossplay with the existing versions on Xbox.
Now 343's Tyler Davis has confirmed in the latest developer update that the team has crossplay "at the top of the list," and that the team plan to release the feature along with regional server selection and input-based matchmaking, meaning using a controller on PC is more likely to match you up with Xbox players.
Davis also talked about what's next for insider testing, stating that Halo 3: ODST was set to start in the first half of this month. It'll include six campaign missions with both single-player and co-op mode, and new features coming to the Firefight mode.
There's a whole list of other cool features coming to the collection too such as Steam account linking, FPS cap adjustment options, and filesharing.