Build Environments 1.3+

Continuing the discussion from :vertical_traffic_light: TRANSMISSION #2: broadcasting the latest from Meteor Forums:

I just finished listening to TRANSMISSION 2.3 (awesome as always), and @sashko talked about the current client and server folders, and how much easier modules makes it to build a mobile-only app (for example), where you just import what you need.

So, I wondered what will become of Meteor.isClient/isServer/isCordova. Given you can build for anything, will we instead see a, where some_name is defined by us appropriately within our codebase? Is that behaviour even needed anymore?